http://www.gemologyproject.com/wiki/api.php?action=feedcontributions&user=Tom+Goodwin%2C+G.G.&feedformat=atomThe Gemology Project - User contributions [en]2024-03-28T20:39:08ZUser contributionsMediaWiki 1.28.0http://www.gemologyproject.com/wiki/index.php?title=Synthetic_cubic_zirconia&diff=8785Synthetic cubic zirconia2010-01-13T23:35:47Z<p>Tom Goodwin, G.G.: Added "ly" to wide</p>
<hr />
<div>{{synthetic cubic zirconia}}<br />
<br />
Synthetic cubic zirconia (CZ) entered the market as a gemstone around 1976 and is till present the most widely used diamond simulant. Although cubic zirconia is found in nature (as minute crystals inside [[zircon]]), the more stable variant of zirconia crystallizes in the monoclinic system (baddeleyite).<br /><br />
The main means of syntheses is through the "[[skull crucible]]" aka "skull melting" method.<br />
<br />
==Chemical composition==<br />
<br />
Zirconia has the chemical formula ZrO<sub>2</sub>, this material however will not crystallize in the cubic system through syntheses. A stabilizer of yttria or calcium oxide needs to be added to the source powder in order to let it crystallize as isotropic crystals.<br />
<br />
==Diagnostics==<br />
<br />
As synthetic cubic zirconia (CZ) is mainly used to imitate [[diamond]] one can expect the main separation techniques to concentrate on distinguishing between the two.<br />
<br />
===Color===<br />
<br />
Synthetic cubic zirconia is produced in a large array of colors, from colorless to black. Many coloring agents, including rare earth elements, are added to the source powder.<br />
* Cesium: yellow, orange, red<br />
* Copper, iron, nickel, praseodymium, titanium: yellow, amber, brown<br />
* Erbium, europium, holmium: pink<br />
* Chromium, thulium, vanadium: green<br />
* Cobalt, manganese, neodymium: lilac, violet, purple, blue<br />
<br />
===Diaphaneity===<br />
<br />
Transparent to opaque.<br />
<br />
===Refractometer===<br />
<br />
Cubic zirconia has an RI that can not be measured with a standard gemological refractometer. There are however other tools available, as the Hanneman-Hodgkinson refractometer or the Brewster angle meter, to determine the RI of CZ.<br />
<br />
The optical properties of CZ vary slightly depending on which, and how much, stabilizer is used (yttria or calcium oxide).<br />
* Yttria stabilized cubic zirconia: RI = 2.171, dispersion = 0.059<br />
* Calcium oxide stabilized cubic zirconia: RI = 2.177, dispersion = 0.065.<br />
<br />
The values of CZ are above the limits of the standard gemological refractometer. There are however a few other tests one can perform.<br />
* The "dot test" will show a ring around the culet if the stone is cut to diamond brilliant proportions.<br />
* The "tilt test" will show leakage.<br />
<br />
===Polariscope===<br />
<br />
CZ may show anomalous extinction.<br />
<br />
===Specific gravity===<br />
<br />
The SG of CZ is about twice that of diamond (3.52) and loose stones will have a higher "heft".<br /><br />
As with the refraction indices, the SG of CZ varies between stabilizers used.<br />
* Yttria stabilized cubic zirconia: SG = 5.95<br />
* Calcium oxide stabilized cubic zirconia: SG = 5.65<br />
<br />
===Hardness===<br />
<br />
* Yttria stabilized cubic zirconia: hardness = 8.25 (Mohs' scale)<br />
* Calcium oxide stabilized cubic zirconia: hardness = 8.5 (Mohs' scale)<br />
<br />
===Luminescence===<br />
<br />
Colorless CZ stabilized by calcium oxide will show a yellow fluorescence.<br />
<br />
==Phenomena==<br />
<br />
Color change synthetic cubic zirconia is not uncommon and may show dramatic changes in natural/incandescent lightning.<br /><br />
Opalline (milky) CZ's are also produced. These are mainly opaque.<br />
<br />
==References==<br />
<br />
* [http://www.google.com/patents?id=9MoEAAAAEBAJ&printsec=abstract&zoom=4&dq=fianit The 1972 patent to create "Fianit" (synth. cubic zirconia) from Lebedev]<br />
* [http://www.amazon.com/gp/product/0750658568?ie=UTF8&tag=gemsandwhywelove&link_code=as3&camp=211189&creative=373489&creativeASIN=0750658568 Gems Their Sources, Descriptions and Identification'' 4th Edition (1990) - Robert Webster (6th ed.)]<br />
<br /><br />
<br /><br />
'''[[Visual_Optics&action=edit| Visual Optics: Needs Content!]]'''<br /><br />
'''Next: [[Video_presentations| Video Presentations]]'''<br />
<br /><br /><br />
'''[[Table_Of_Contents| Return to the Table of Contents]]'''</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=User:Tom_Goodwin,_G.G.&diff=8784User:Tom Goodwin, G.G.2010-01-13T23:21:39Z<p>Tom Goodwin, G.G.: Edited OUT previous association with "Las Vegas Jewelers"</p>
<hr />
<div>'''Thomas E. Goodwin, B.A., A.Sc.G., G.G.,'''<br />
http://www.graduategemologist.blogspot.com <br />
<br />
==Education==<br />
<br />
''Foothill High School, Santa Ana, Califonia, 1967<br />
<br />
''A.A., Santa Ana College, Liberal Arts, 1969<br />
<br />
''B.A., California State University, Fullerton, Psychology, 1974<br />
<br />
''A.Sc.G., (Associate in Science in Gemology) Santa Ana College, 1981<br />
<br />
''Certificate in Gemology, Santa Ana College, 1981<br />
<br />
''Graduate Gemologist Diploma, Gemological Institute of America, Santa Monica, California, 1985</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Help:Contents&diff=8129Help:Contents2009-09-07T14:24:46Z<p>Tom Goodwin, G.G.: changed "not allowed" to "not permissible"</p>
<hr />
<div>==Editting help==<br />
<br />
===Editing a page===<br />
<br />
Find the page you want to edit. Click on the "Edit" button (the 3rd tab on the top of this page, OR the mini ''[edit]'' on the right). This should open an editing interface. Try and follow the same format as the rest of the page. In the beginning, you might find it easier to copy some portion of the page that looks similar in format to what you want to add, paste it where you want to appear in the page, and edit it. As you get closer to becoming a master at the art of wiki editing, you might want to refer to '''Text Formatting Rules''' (see below)<br />
<br />
===Previewing & changing pages===<br />
<br />
When you are done editing, click on the '''Show preview''' button below the editing box. This will open a page with the current page's preview, and the page editing interface below it. If you choose, you can make some more changes using the editing interface. When you are done, click the '''Save page''' button below, and your editing will be saved for online viewing.<br />
<br />
===Text formatting rules & Tables===<br />
<br />
If you click on this<br />
[http://meta.wikimedia.org/wiki/Help:Contents#For_editors page], it directs you to most of the formatting info you will need.<br />
<br />
For creating tables in this wiki, there is a small tutorial in [[Help:Table]].<br />
To access a prefab blank table for gemstone descriptions click:[[TableTemplate]]<br />
<br />
===Use of third party information and images===<br />
<br />
All information you copy from other sources should be done with permission from the author or the original author should be fully aknowledged. There are several ways to do this. The most common way is to mention the source at the bottom of each page in the "Sources" section.<br /><br />
Images you use should carry the same written permission from the creator and they should be attributed (preferably in the comment when you upload the file).<br />
<br />
===Spelling and grammar===<br />
<br />
We use US-En spelling and grammar.<br /><br />
Names of gemstones are not capitalized, unless at the start of a sentence<br />
<br />
===Advertising===<br />
<br />
It is not permissible to advertise your products, books, website or anything else on the pages. The only exception is that when a large part of information comes from a source that is your own and only then in the "Sources" section at the bottom of the page you are editing.<br />
<br />We reserve the right to edit out anything that violates this rule.<br />
<br />
===Sharing information and copyright===<br />
<br />
When you contribute to The Gemology Project, you can not change your mind later (for whichever reason) and delete your contributions. You will not transfer copyright to The Gemology Project when you share your information, but you explicitly give us everlasting permission to publish it.<br />
<br />
==See also==<br />
<br />
* [[Frequently_Asked_Questions|FAQ]]<br />
<br />
* [[The_Gemology_Project:General_disclaimer|Disclaimer]]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Introduction_to_Gemology&diff=5841Introduction to Gemology2007-03-15T00:41:56Z<p>Tom Goodwin, G.G.: Added Robert Shipley as founder of the GIA</p>
<hr />
<div>==General information on Gemology==<br />
<br />
===What is Gemology?===<br />
<br />
'''Gemology''' is the scientific study of gemstones, which often involves the study of mineralogical fundamentals such as formations, genesis, localities, physical properties and identification of gemstones. It includes the basic knowledge of structural, crystallographic, chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned.<br />
<br />
''Special Gemology'' deals with categories and varieties of gemstones, synthetic stones and imitations. Conventionally, the organic substances such as amber, pearls, coral and the non-minerals are also included in this subject of special gemology.<br />
<br />
''Practical Gemology'' refers to the application of the knowledge of characteristics and properties of gemstones in identification or separation of synthetics and imitations. Diamond grading is included in practical gemology.<br />
<br />
===What is a Gemologist?===<br />
<br />
A gemologist is someone who studies gemstones. Being recognized as a gemologist usually involves having credentials from one of the Institutes for Gem(m)ological Studies discussed below (see '''Becoming a Gemologist''' below).<br />
<br />
===What are gemstones?===<br />
<br />
Gemstones are usually [[mineral]]s but sometimes [[organic | <SPAN title=" derived from a living organism " class="popup">organic</SPAN>]] substances.<br />
What separates them from minerals in general is that they are used in jewelry or for ornamentation. That is a very thin line of separation, but usually we take 4 factors into account:<br />
<br />
* [[Durability]]<br />
* [[Rarity]]<br />
* [[Beauty]]<br />
* [[Acceptability]]<br />
<br />
And, of course, there is a 5th factor:<br />
<br />
* [[Fashion]] <br />
<br />
All the factors above are relative in nature. For instance, [[amber]] has very poor durability, isn't very rare and in general is not highly priced. Yet it is considered to be a gem due to its beauty.<br />
<br />
On the other hand, most [[sapphire]] has good durability but can be very unattractive and inexpensive. Only a small portion of all sapphires mined have good color/beauty. The same can be said for [[diamond]]; the vast majority of diamonds mined are used for industrial purposes because they lack the necessary beauty to be worn as jewelery.<br />
<br />
==Becoming a Gemologist==<br />
<br />
Becoming a gemologist in general means hard work and commitment. A wise teacher once said "You are only permitted to read books related to our trade and a religious book of your choice from now on . . . for the rest of your life".<br />
<br />
===Education===<br />
<br />
Although you can find very useful information on the Internet (like here), we '''strongly''' suggest that you take formal training from one of the established institutes listed below. Our editors have graduated from at least one of them.<br />
<br />
====Gem-A====<br />
<br />
Better known as The Gemmological Association and Gem Testing Laboratory of Great Britain, this school is London based with departments worldwide. It offers distance tutoring as well as teaching centers.<br><br />
The primary focus is on in-depth theory and the exams are the hardest to take in the industry. A fellowship of Gem-A means esteem. <br />
<br />
Costs:<br />
<br />
Foundation correspondence course GBP 993.00<br><br />
Diploma correspondence course GBP 1356.00 (on completion is granted the FGA title).<br />
<br />
Gem Diamond diploma course GBP 1584.00 (on completion is granted the DGA title).<br />
<br />
Website http://gem-a.info/<br />
<br />
====GIA====<br />
<br />
The Gemological Institute of America is the most prestigious and respected institute for gemology within the United States. Its main location is in Carlsbad, California, with facilities in New York and Los Angeles. Courses may be completed by distance learning via the online "virtual campus".<br />
It was established in 1931 by Robert Shipley, and currently the GIA is the world’s largest and one of the most respected nonprofit institutes of gemological research and learning internationally.<br />
It employs nearly 900, including scientists, diamond graders, and educators.<br />
<br />
Costs:<br />
<br />
On campus (CB/NY/LA): 6 month continuous program (780 hours) $13,995<br />
<br />
Distance Education: GEM130, GEM230, GEM230L, GEM120, GEM220,GEM220L, GEM240, GEM240L (Maximum completion time: 63 months) $6,975 ($7,395 International)<br />
<br />
What you earn: Graduate Gemologist Diploma, Graduate Diamonds Diploma, Graduate Colored Stones Diploma<br><br />
Website: http://www.gia.edu<br />
<br />
====AIGS====<br />
Thailand is in the heart of Southeast Asia's gem and jewelry production and trading area. It presents you with an extraordinary opportunity to learn gemology in theory and practice while experiencing the gem business in a three dimensional way. <br />
<br />
The A.G. program, which leads to the A.G. (Accredited Gemologist) Diploma, includes the four core courses:<br> <br />
:E102: Gem Identification<br><br />
:E103: Diamond Grading and Pricing<br><br />
:E201: Colored Stone Grading and Pricing<br><br />
:E301: Synthetic and Treated Gem Identification. <br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthetics and Treated Gems”. <br />
<br />
Students enrolling in the entire A.G. program are entitled to a 15% discount off the total tuition fee. Courses must be taken within one year of the first date of payment. Beyond the one year period, students will be subjected to any tuition increases that may have occurred. (Example: Old fee = 20,000 Baht, New fee in effect since date of enrollment = 22,000 Baht, Additional amount to be paid = 2,000 Baht.)<br />
<br />
Living expenses and general overhead are amazingly low compared to countries such as USA, Japan and most of Europe. Students studying at the AIGS can live with a US$600 to US$1000 budget per month including housing near the school, weekend field trips, restaurants and entertainment. Of course, you can spend much more if you want to, but this amount yields a comfortable lifestyle!<br><br />
Website: http://www.aigsthailand.com/<br />
<br />
====DGemG====<br />
The Deutsche Gemmologische Gesellschaft (The Educational Training Center of the German Gemmological Association) is located in Idar-Oberstein, Germany. Idar-Oberstein is an international colored stone gem capital, where gem cutting has been traditionally mastered for centuries. It is currently bustling with local gem artists and studios. It has, perhaps, the highest per capita population of gem cutters in the world! The German Gemmological Association was founded in 1932.<br />
Its laboratories have modern state of the art equipment, and one of the most extensive colored and exotic gemstone collections available.<br />
<br />
Costs:<br />
<br />
Euro 5,800.00 <br><br />
<br />
Website:http://www.dgemg.de/gemmologen_eng/index.php?seite=home<br />
<br />
====FGAA====<br />
<br />
The Gemmological Association of Australia (GAA), founded in 1945, is Australia’s historic trade-accepted non-profit educational authority for gemology. <br><br />
They offer gemological courses in 6 state divisions.<br />
<br />
Costs: contact one of the six state divisions for pricing.<br />
<br />
Website: [http://www.gem.org.au www.gem.org.au]<br />
<br />
====CGA====<br />
<br />
The Canadian Gemmological Association, based in Toronto Canada, is a Canada-wide professional organization which has set the standard for excellence in the practice of gemology. It was founded in 1958 by Dean S.M. Field, and has since provided training in gemology to persons dealing with gemstones in the jewelery industry and to hobbyists for better appreciation and possible new career opportunities within gemology.<br />
<br />
They offer a one-year correspondence course as well classes on location.<br />
<br />
Costs:<br />
<br />
The two-year correspondence course, leading to a Diploma in Gemmology and a Fellowship (FCGmA) in the Canadian Gemmological Association, is offered for CAD 2,020.00<br />
<br />
Website [http://www.canadiangemmological.com/ canadagemmological.com]<br />
<br />
===Post Graduate===<br />
<br />
After gaining your gemological diploma, the real fun starts. You will know the basics and more importantly you will know how to understand the many articles published in various [[periodicals]].<br><br />
If you keep up as a consumer of the gemological literature and are involved with continuing education, you will be a good gemologist one day.<br />
<br />
====Career Opportunities====<br />
<br />
As with any profession, it is all up to you what you will become and what your salary will be.<br />
<br />
Think of a gemological diploma as if you have finished your first year in college and the pay rate according to that when you start out. You will be qualified to find jobs in gemological laboratories worldwide and will be the key figure in the local jewelry store. You may become manager of a telsell company, start your own gem trading business, become an appraiser, or you might just stay shoveling municipal gardens etc. Anything you set your mind to. Pay rate is according to experience and market.<br /><br />
Our best advice is to start networking from the start and to seek a new employer every few years so you can gain as much know-how as you can.</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Introduction_to_Gemology&diff=5840Introduction to Gemology2007-03-14T22:11:03Z<p>Tom Goodwin, G.G.: Changed "correspondence courses" to distance learning and added GIA's "Virtual Campus"</p>
<hr />
<div>==General information on Gemology==<br />
<br />
===What is Gemology?===<br />
<br />
'''Gemology''' is the scientific study of gemstones, which often involves the study of mineralogical fundamentals such as formations, genesis, localities, physical properties and identification of gemstones. It includes the basic knowledge of structural, crystallographic, chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned.<br />
<br />
''Special Gemology'' deals with categories and varieties of gemstones, synthetic stones and imitations. Conventionally, the organic substances such as amber, pearls, coral and the non-minerals are also included in this subject of special gemology.<br />
<br />
''Practical Gemology'' refers to the application of the knowledge of characteristics and properties of gemstones in identification or separation of synthetics and imitations. Diamond grading is included in practical gemology.<br />
<br />
===What is a Gemologist?===<br />
<br />
A gemologist is someone who studies gemstones. Being recognized as a gemologist usually involves having credentials from one of the Institutes for Gem(m)ological Studies discussed below (see '''Becoming a Gemologist''' below).<br />
<br />
===What are gemstones?===<br />
<br />
Gemstones are usually [[mineral]]s but sometimes [[organic | <SPAN title=" derived from a living organism " class="popup">organic</SPAN>]] substances.<br />
What separates them from minerals in general is that they are used in jewelry or for ornamentation. That is a very thin line of separation, but usually we take 4 factors into account:<br />
<br />
* [[Durability]]<br />
* [[Rarity]]<br />
* [[Beauty]]<br />
* [[Acceptability]]<br />
<br />
And, of course, there is a 5th factor:<br />
<br />
* [[Fashion]] <br />
<br />
All the factors above are relative in nature. For instance, [[amber]] has very poor durability, isn't very rare and in general is not highly priced. Yet it is considered to be a gem due to its beauty.<br />
<br />
On the other hand, most [[sapphire]] has good durability but can be very unattractive and inexpensive. Only a small portion of all sapphires mined have good color/beauty. The same can be said for [[diamond]]; the vast majority of diamonds mined are used for industrial purposes because they lack the necessary beauty to be worn as jewelery.<br />
<br />
==Becoming a Gemologist==<br />
<br />
Becoming a gemologist in general means hard work and commitment. A wise teacher once said "You are only permitted to read books related to our trade and a religious book of your choice from now on . . . for the rest of your life".<br />
<br />
===Education===<br />
<br />
Although you can find very useful information on the Internet (like here), we '''strongly''' suggest that you take formal training from one of the established institutes listed below. Our editors have graduated from at least one of them.<br />
<br />
====Gem-A====<br />
<br />
Better known as The Gemmological Association and Gem Testing Laboratory of Great Britain, this school is London based with departments worldwide. It offers distance tutoring as well as teaching centers.<br><br />
The primary focus is on in-depth theory and the exams are the hardest to take in the industry. A fellowship of Gem-A means esteem. <br />
<br />
Costs:<br />
<br />
Foundation correspondence course GBP 993.00<br><br />
Diploma correspondence course GBP 1356.00 (on completion is granted the FGA title).<br />
<br />
Gem Diamond diploma course GBP 1584.00 (on completion is granted the DGA title).<br />
<br />
Website http://gem-a.info/<br />
<br />
====GIA====<br />
<br />
The Gemological Institute of America is the most prestigious and respected institute for gemology within the United States. Its main location is in Carlsbad, California, with facilities in New York and Los Angeles. Courses may be completed by distance learning via the online "virtual campus".<br />
It was established in 1931, and currently the GIA is the world’s largest and one of the most respected nonprofit institutes of gemological research and learning internationally.<br />
It employs nearly 900, including scientists, diamond graders, and educators.<br />
<br />
Costs:<br />
<br />
On campus (CB/NY/LA): 6 month continuous program (780 hours) $13,995<br />
<br />
Distance Education: GEM130, GEM230, GEM230L, GEM120, GEM220,GEM220L, GEM240, GEM240L (Maximum completion time: 63 months) $6,975 ($7,395 International)<br />
<br />
What you earn: Graduate Gemologist Diploma, Graduate Diamonds Diploma, Graduate Colored Stones Diploma<br><br />
Website: http://www.gia.edu<br />
<br />
====AIGS====<br />
Thailand is in the heart of Southeast Asia's gem and jewelry production and trading area. It presents you with an extraordinary opportunity to learn gemology in theory and practice while experiencing the gem business in a three dimensional way. <br />
<br />
The A.G. program, which leads to the A.G. (Accredited Gemologist) Diploma, includes the four core courses:<br> <br />
:E102: Gem Identification<br><br />
:E103: Diamond Grading and Pricing<br><br />
:E201: Colored Stone Grading and Pricing<br><br />
:E301: Synthetic and Treated Gem Identification. <br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthetics and Treated Gems”. <br />
<br />
Students enrolling in the entire A.G. program are entitled to a 15% discount off the total tuition fee. Courses must be taken within one year of the first date of payment. Beyond the one year period, students will be subjected to any tuition increases that may have occurred. (Example: Old fee = 20,000 Baht, New fee in effect since date of enrollment = 22,000 Baht, Additional amount to be paid = 2,000 Baht.)<br />
<br />
Living expenses and general overhead are amazingly low compared to countries such as USA, Japan and most of Europe. Students studying at the AIGS can live with a US$600 to US$1000 budget per month including housing near the school, weekend field trips, restaurants and entertainment. Of course, you can spend much more if you want to, but this amount yields a comfortable lifestyle!<br><br />
Website: http://www.aigsthailand.com/<br />
<br />
====DGemG====<br />
The Deutsche Gemmologische Gesellschaft (The Educational Training Center of the German Gemmological Association) is located in Idar-Oberstein, Germany. Idar-Oberstein is an international colored stone gem capital, where gem cutting has been traditionally mastered for centuries. It is currently bustling with local gem artists and studios. It has, perhaps, the highest per capita population of gem cutters in the world! The German Gemmological Association was founded in 1932.<br />
Its laboratories have modern state of the art equipment, and one of the most extensive colored and exotic gemstone collections available.<br />
<br />
Costs:<br />
<br />
Euro 5,800.00 <br><br />
<br />
Website:http://www.dgemg.de/gemmologen_eng/index.php?seite=home<br />
<br />
====FGAA====<br />
<br />
The Gemmological Association of Australia (GAA), founded in 1945, is Australia’s historic trade-accepted non-profit educational authority for gemology. <br><br />
They offer gemological courses in 6 state divisions.<br />
<br />
Costs: contact one of the six state divisions for pricing.<br />
<br />
Website: [http://www.gem.org.au www.gem.org.au]<br />
<br />
====CGA====<br />
<br />
The Canadian Gemmological Association, based in Toronto Canada, is a Canada-wide professional organization which has set the standard for excellence in the practice of gemology. It was founded in 1958 by Dean S.M. Field, and has since provided training in gemology to persons dealing with gemstones in the jewelery industry and to hobbyists for better appreciation and possible new career opportunities within gemology.<br />
<br />
They offer a one-year correspondence course as well classes on location.<br />
<br />
Costs:<br />
<br />
The two-year correspondence course, leading to a Diploma in Gemmology and a Fellowship (FCGmA) in the Canadian Gemmological Association, is offered for CAD 2,020.00<br />
<br />
Website [http://www.canadiangemmological.com/ canadagemmological.com]<br />
<br />
===Post Graduate===<br />
<br />
After gaining your gemological diploma, the real fun starts. You will know the basics and more importantly you will know how to understand the many articles published in various [[periodicals]].<br><br />
If you keep up as a consumer of the gemological literature and are involved with continuing education, you will be a good gemologist one day.<br />
<br />
====Career Opportunities====<br />
<br />
As with any profession, it is all up to you what you will become and what your salary will be.<br />
<br />
Think of a gemological diploma as if you have finished your first year in college and the pay rate according to that when you start out. You will be qualified to find jobs in gemological laboratories worldwide and will be the key figure in the local jewelry store. You may become manager of a telsell company, start your own gem trading business, become an appraiser, or you might just stay shoveling municipal gardens etc. Anything you set your mind to. Pay rate is according to experience and market.<br /><br />
Our best advice is to start networking from the start and to seek a new employer every few years so you can gain as much know-how as you can.</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Iolite&diff=5830Iolite2007-03-10T22:39:49Z<p>Tom Goodwin, G.G.: /* Pleochroism */</p>
<hr />
<div>{{iolite}}<br />
<br />
[[Image:Iolite_small.jpg|framed|left| Marquise Shaped Faceted Iolite, courtesy of Richard Kocerek.]]<br clear="left" /><br />
Iolite is also named "water sapphire", cordierite or dichroite. Iolite has been worn for centuries and derives its name from “Ios” - the Greek word for violet. Due to it’s strong pleochroism, ancient Vikings used iolite for navigation on cloudy days. The gemstone acted as a polarizing filter and allowed the ancient sailors to determine the position of the sun. The soft blue color makes it a very attractive gemstone. Iolite is the 21st anniversary gemstone.<br />
<br />
==Diagnostics==<br />
<br />
Iolite may be confused (due to its color) with [[sapphire]] and [[tanzanite]].<br />
<br />
===Color===<br />
<br />
Iolite is usually blue to violetish-blue. Rarely it is colorless.<br />
<br />
===Magnification===<br />
<br />
Iolite is a type II stone in the GIA clarity grading system is usually included.<br />
Typical inclusions are:<br />
* liquid feathers<br />
<br />
===Optical and physical properties===<br />
<br />
Although iolite is usually confused with sapphire and tanzanite due to its color, its optical properties will distinguish iolite from them easily.<br />
<br />
====Pleochroism====<br />
<br />
Iolite is very strongly trichroic and this is the primary test in seperating iolite from other gemstones. The three colors you will find are through dichroscopic examination are:<br />
# violet-blue<br />
# pale-blue<br />
# pale yellow<br />
<br />
Sapphire is dichroic and although unheated tanzanite is also trichroic like iolite, the heated tanzanite is dichroic. Natural unheated tanzanite is very rare.<br />
<br />
====Refractometer====<br />
<br />
Iolite is biaxial with a negative optic sign. The β ray is almost halfway between α and γ so precise readings should be taken.<br />A typical reading will be n<sub>α</sub> = 1.535-1.539 and n<sub>γ</sub> = 1.540-1.543<br /><br />
The maximum birefringence ranges from 0.008 to 0.012<br /><br />
Tanzanite is also biaxial but has a positive optic sign and its values are too high to indicate iolite. Sapphire is uniaxial and the readings are also too high.<br />
<br />
Quartz has RI readings in the range of iolite, but is uniaxial.</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Alexandrite&diff=5829Alexandrite2007-03-10T22:36:06Z<p>Tom Goodwin, G.G.: Added "chromophores" to describe the coloring agents vanadium and chromium</p>
<hr />
<div>{{alexandrite}}<br />
<br />
Alexandrite is a phenomenal variety of the mineral [[chrysoberyl]]. Because of the trace amounts of the chromophores vanadium and chromium, alexandrite appears different colors depending on whether it is viewed in natural or incandescent light. In daylight, the stone appears to be green; in artificial light it appears to be raspberry red. It was originally discovered in the Ural Mountains in 1830 on the birthday of Czar Alexander of Russia. Another extraordinary coincidence was that the national colors of Russia were red and green. Today, alexandrite is found in Brazil and to a lesser extent in Africa. Alexandrite has long been associated with great luck and prosperity.<br />
<br />
==Additional Phenomena==<br />
*Cat's Eye<br />
<br />
[[Image:Alex-blue.gif|left|thumb|250px|Cat's eye Alexandrite under daylight<br />Photo courtesy of The Gem Trader]] <br clear="all" /><br />
[[Image:Alex-purple.gif|left|thumb|250px|Cat's eye Alexandrite under incandescent light<br />Photo courtesy of The Gem Trader]]<br />
<br clear="all" /></div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Alexandrite&diff=5827Talk:Alexandrite2007-03-10T00:47:44Z<p>Tom Goodwin, G.G.: Confirmation of Cat's Eye Alexandrite photos appearing in body of article.</p>
<hr />
<div>I added cat's eye photos to this page, it shows up fine in preview, but when I save the page, the images don't appear!!!!!!!!!!! What is going on?--[[User:Africanuck|Africanuck]] 23:51, 7 March 2007 (PST)<br />
* The cat's eye photos show up on my system just fine, Africanuck. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 16:47, 9 March 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Rock_Crystal&diff=5777Talk:Rock Crystal2007-02-28T21:47:18Z<p>Tom Goodwin, G.G.: Added "spheres"</p>
<hr />
<div>===Gem Photograph===<br />
<br />
I thought I would start this article with the most notable and well known use of rock crystal as "crystal balls," although we know that the Gypsy "fortune-tellers" and the like use polished glass spheres instead. It would be nice if we could find a suitable photograph of a genuine "crystal ball" to establish the authenticity of the genuine material. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 12:18, 20 January 2007 (PST)<br />
<br />
:I'm not sure why you would put fortune-tellers between quotes. Madam Voyante looked in her ball many years ago and predicted I would never amount to anything and that it would rain in the next month. Seems she saw right. <br />
:As far as I am concerned "fortune-tellers" don't tell fortunes. They just collect money! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 12:53, 20 January 2007 (PST)<br />
:A good pic of a rock crystal would be nice, especially if it shows an interference flash --[[User:Doos|Doos]] 12:32, 20 January 2007 (PST)<br />
<br />
I have a few crystal balls at home. I'll see what I can conjure up for you. I wrote an article on crystal gazing several years ago. I'm not sure I still have a copy, but I'll see what I can remember--[[User:Barbra|Barbra]] 12:48, 20 January 2007 (PST)<br />
:: Will you tell me my "fortune," Barbra? ;) [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 12:56, 20 January 2007 (PST)<br />
<br />
I wish I could Tom,lol. I hope you don't mind I put in a couple extra things into your rock crystal page, and added a couple pics. I looked at my xl ball thru crossed polaroids and did get the crossed isogyres but the bulls eye was really weak and unphotographable (is that a word?) [[User:Barbra|Barbra]]<br />
::It's OUR rock crystal page, Barbra! Thank You for adding the photos. We are on our way here! Incidentally, I think you were searching for the word "unphotogenic." Right? [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 03:26, 22 January 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Luminescence&diff=5739Talk:Luminescence2007-02-18T04:57:05Z<p>Tom Goodwin, G.G.: Notice that TeneScap.gif image is broken.</p>
<hr />
<div>5.1.06: gemma just checked for spelling and any really off grammar. i will actually read it thoroughly now. :-) -- oops missed a comma after Pope County and I now see two spellings of Jablonski. arghh. "I'll be baaacckkkk!"<br />
*Since none of us apparently majored in the English language, I think spelling errors are to be expected. Somebody like me (a dyed-in-the-wool YANK) will come along and spoil your day with corrections. ;) [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 16:28, 16 January 2007 (PST)<br />
<br />
== Scapolite data ==<br />
<br />
* The data on scapolite (tenebrescence) is changed to 10-15 minutes. My test was done with a UVP UVG4 portable lamp, what lamp was used that resulted in 10-15 minutes? --[[User:Doos|Doos]] 07:44, 17 January 2007 (PST)<br />
::The photograph file TenebScap.gif (before sw-uv radiation) doesn't appear, although I checked the file and it is appeared when I keyed it up. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 20:57, 17 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Introduction_to_Gemology&diff=5738Talk:Introduction to Gemology2007-02-18T04:37:07Z<p>Tom Goodwin, G.G.: Comment on "cachet" with Doos</p>
<hr />
<div>== quick draft ==<br />
<br />
This is just a quick draft of what it could look like, feel free to edit --[[User:Doos|Doos]] 12:44, 1 February 2006 (PST)<br />
<br />
:Shouldn't availability also be part of the "what makes a gemstone" section? Africanuck, March 8<br />
<br />
Yes that is a big part of it, but that is covered in "rarity". Although "availability" and "rarity" are usually the same factors, it may be artificial. Like the diamond cartel and probably also tanzanite. Furthermore politcs may play a role in this. For the most part this is not the case fortunatly. Feel free to define "rarity". --[[User:Doos|Doos]] 14:50, 8 March 2006 (PST)<br />
<br />
Ok, I pulled out my FGA stuff, what they list is acceptability (not availability, you are right that is rarity, silly me) but don't list price as a criteria.... You probably know more than I, but some of the stones that are considered gemstones are pretty cheap, and I'm not too clear on how price enter into it other than as a reflection of it's desirability (often dictated by fashion) and availability?<br />
<br />
One other question, is that supposed to be inorganic or organic? --[[User:Africanuck|Africanuck]] 06:51, 9 March 2006 (PST)<br />
<br />
:oops, organic ofcourse. You are right, let's drop "price". --[[User:Doos|Doos]] 07:16, 9 March 2006 (PST)<br />
<br />
changed inorganic to organic and changed price to acceptability --[[User:Africanuck|Africanuck]] 07:35, 9 March 2006 (PST)<br />
<br />
I'm also kind of wondering if "fashion" really fits in there... it's not really a criteria of whether or not a stone is a gem, and might be more appropriate to have it as part of the acceptability or rarity definitions. Or if we are going to touch on the subject of value, it might be added there. What do you think? --[[User:Africanuck|Africanuck]] 11:08, 10 March 2006 (PST)<br />
<br />
:Well fashion is a factor for much of the lower end gemstones (and at times for higher ends). If you look at the early 19th century you will find that lava stone was used widely in jewelry. Although we don't regard lava stone anything more than a curiousity in antique jewelry (studies showed that many of it was mere cement), it was used extensive in jewelry then (mainly due to the excavations of Pompeii and Herculanium). Painite is a new craze and might well be incorperated more a more into jewelry, also transforming it from a mineral into a gem. Ammolite is another example, it hardly passes the durability/rarity test. Yet many people seem to like it. So fashion plays a role. It's a thin line, a very thin one in many cases. --[[User:Doos|Doos]] 12:27, 10 March 2006 (PST)<br />
<br />
:Maybe acceptability/fashion .. I could feel comfortable with that. --[[User:Doos|Doos]] 12:32, 10 March 2006 (PST)<br />
*Antoinette Matlins uses the term "cachet" to describe the attraction that some gemstones convey in terms of "fashion." [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 18:39, 14 February 2007 (PST)<br />
<br />
:My understanding of "cachet" has a "classy" factor in it. --[[User:Doos|Doos]] 10:45, 15 February 2007 (PST)<br />
::Classy is a very good way to describe it Doos. As in a padparadscha sapphire with vivid saturation, perhaps? [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 20:37, 17 February 2007 (PST)<br />
== rollback ==<br />
<br />
Africa edited the Gem-A section and I tested the rollback .. so I needed to put her edits back by hand. Use 'rollback' with care so it seems.<br />
<br />
== AIGS section ==<br />
<br />
In the AIGS section, the following paragraphs are confusing to me. Any help on this?<br />
<br />
"The A.G. (Accredited Gemologist ) Diploma :<br />
<br />
The A.G. program includes the 4 core courses: E102: Gem Identification, E103: Diamond Grading and Pricing, E201: Colored Stone Grading and Pricing, E301: Synthetic and Treated Gem Identification.<br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthethics and Treated Gems”. "<br />
<br />
also, i think CGA should be added to educational institutes.<br />
<br />
: I can read it alright, but if it's confusing for you, then probably to others aswell.Is it the numbers that make it hard to read (eg. E102 etc)? I added the cga.--[[User:Doos|Doos]] 06:33, 28 February 2006 (PST)<br />
<br />
thanks for the CGA, doos. what confuses me about AIGS is the first line with the colon -- what does that refer to? to the following paragraphs? i see now that the last two really do link up fine (the paragraphing confused me but now i see it is ok). it is the first line that seems to be hanging in the wind, to me anyway.<br />
<br />
:I think that refers to the module codes of the courses. I didn't write that part so I dont really know. Rewrite it if you think that could be clearer.<br />
<br />
<br />
ok, did. check it out to see if i botched it.<br />
<br />
== tellsell ==<br />
<br />
under career opps, what is a "tellsell company"? [[User:Gemma|Gemma]] 20:35, 2 November 2006 (PST)<br />
: maybe that should read "telsell"? .. like JTV --[[User:Doos|Doos]] 07:13, 3 November 2006 (PST)<br />
<br />
that makes sense, thanks [[User:Gemma|Gemma]] 16:53, 3 November 2006 (PST)<br />
<br />
spell checked and edited [[User:Gemma|Gemma]] 20:19, 6 November 2006 (PST)<br />
<br />
== Definition of Gemologist ==<br />
A lot of people (like rockhounds) study gem minerals. Does that make them academically trained? When I think of anyone who is a "ologist" I think of formal academic training and achievement to attain such a title. In my opinion, because of this, the definition of "gemologist" needs to be edited and expanded here reflecting the professional full time work and dedication involved. I know a lot of amateur "gemologists" who couldn't separate glass from diamond. NO JOKE! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 17:32, 14 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Ruby&diff=5736Talk:Ruby2007-02-16T21:27:35Z<p>Tom Goodwin, G.G.: </p>
<hr />
<div>'''Pectolite Page Example For Organizing this Article?'''<br />
<br />
I just took a look at the article on Pectolite and found that the information seems to be nicely organized in 10 categories. In my opinion, we ought to adopt a standard where all of the articles are categorized in the same way. Then, we would have a measure of uniformity where information could be added with a focus on specialization of fact. I think the Pectolite page just about sums everything up in a nice format. Anybody else think that this would be efficacious? [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:40, 18 January 2007 (PST)<br />
<br />
:We have been discussing it this week and are searching for a logical format for the gem pages. The site is still in its infant days, so we are still learning how to do it best. When we feel comfortable with a specific format, we will make an example page. Thanks for the input. --[[User:Doos|Doos]] 14:51, 18 January 2007 (PST)<br />
* Very good. An example page will serve us all well! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 15:06, 18 January 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Kyanite&diff=5720Talk:Kyanite2007-02-15T02:48:17Z<p>Tom Goodwin, G.G.: </p>
<hr />
<div>==Variable Hardness==<br />
This gem is difficult to facet because of the variable hardness. 7 across the width of the crystal and 5 along the length,(Webster). We can write about this in the text of the article. Therefore, at present; I am omitting the hardness in the template box until we can have some further discussion about what to do. The cleavage is perfect, and in two directions, easily developed too. More difficulty in cutting is due to fracture planes caused by multiple twinning. The fractures are seen as inclusions in all faceted kyanites according to the Larousse Encyclopedia which I frequently cite here. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:39, 6 February 2007 (PST)<br />
* Barbra has a section on her 4.37 carat emerald-cut kyanite over on the forum and it is fracture free. In light of this, it appears that we have found an error in the Larousse Encyclopedia regarding their statement of fractures seen as inclusions in ALL faceted kyanites. Because of this, I am going to have to fact-check ALL of the Larousse information that I use here.[[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:34, 9 February 2007 (PST)<br />
::Almost all cut gems are fracture free. That doesn't mean they don't fracture when you apply force on them. Maybe there is some confusion between fracture and parting. --[[User:Doos|Doos]] 09:27, 10 February 2007 (PST)<br />
:::There IS confusion. For instance, "false" parting in corundum. In my view, "parting" is confused also with "cleavage." [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]]<br />
::::Indeed a very usual confusion. Maybe Larousse meant that all rough kyanite is fractured, not the cut. --[[User:Doos|Doos]] 13:51, 10 February 2007 (PST)<br />
:::::Barbra has carefully examined her kyanite and it is like she said, fracture-free. She posted some microphotographs of it on the forum and is trying to identify other inclusions. If kyanite is SUPPOSED to be always fractured after faceting, she has possession of the rare exception to the rule, as per Larousse. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 23:45, 13 February 2007 (PST)<br />
==Polymorphic==<br />
Kyanite is a polymorph with andalusite and fibrolite. Perhaps this will be useful when the introduction is written. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 16:01, 6 February 2007 (PST)<br />
:Yes of course it should be included (although maybe sillimanite is a more gemmo name for fibrolite). --[[User:Doos|Doos]] 13:53, 10 February 2007 (PST)<br />
:: Agreed. sillimanite is a better name, gemologically. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 23:49, 13 February 2007 (PST)<br />
:::For the project it might be best to cross reference to each other as both might be an option in a search. --[[User:Doos|Doos]] 10:08, 14 February 2007 (PST)<br />
* Very good. A cross reference will work well. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 13:17, 14 February 2007 (PST)<br />
==kyanite photograph==<br />
I don't know about anyone else, but this photo shows up with poor resolution on my monitor. There is an apparent lack of contrast with the dark background. Otherwise the stone looks very nice. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 18:47, 14 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Kyanite&diff=5719Talk:Kyanite2007-02-15T02:47:48Z<p>Tom Goodwin, G.G.: Comment on kyanite photograph.</p>
<hr />
<div>==Variable Hardness==<br />
This gem is difficult to facet because of the variable hardness. 7 across the width of the crystal and 5 along the length,(Webster). We can write about this in the text of the article. Therefore, at present; I am omitting the hardness in the template box until we can have some further discussion about what to do. The cleavage is perfect, and in two directions, easily developed too. More difficulty in cutting is due to fracture planes caused by multiple twinning. The fractures are seen as inclusions in all faceted kyanites according to the Larousse Encyclopedia which I frequently cite here. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:39, 6 February 2007 (PST)<br />
* Barbra has a section on her 4.37 carat emerald-cut kyanite over on the forum and it is fracture free. In light of this, it appears that we have found an error in the Larousse Encyclopedia regarding their statement of fractures seen as inclusions in ALL faceted kyanites. Because of this, I am going to have to fact-check ALL of the Larousse information that I use here.[[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:34, 9 February 2007 (PST)<br />
::Almost all cut gems are fracture free. That doesn't mean they don't fracture when you apply force on them. Maybe there is some confusion between fracture and parting. --[[User:Doos|Doos]] 09:27, 10 February 2007 (PST)<br />
:::There IS confusion. For instance, "false" parting in corundum. In my view, "parting" is confused also with "cleavage." [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]]<br />
::::Indeed a very usual confusion. Maybe Larousse meant that all rough kyanite is fractured, not the cut. --[[User:Doos|Doos]] 13:51, 10 February 2007 (PST)<br />
:::::Barbra has carefully examined her kyanite and it is like she said, fracture-free. She posted some microphotographs of it on the forum and is trying to identify other inclusions. If kyanite is SUPPOSED to be always fractured after faceting, she has possession of the rare exception to the rule, as per Larousse. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 23:45, 13 February 2007 (PST)<br />
==Polymorphic==<br />
Kyanite is a polymorph with andalusite and fibrolite. Perhaps this will be useful when the introduction is written. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 16:01, 6 February 2007 (PST)<br />
:Yes of course it should be included (although maybe sillimanite is a more gemmo name for fibrolite). --[[User:Doos|Doos]] 13:53, 10 February 2007 (PST)<br />
:: Agreed. sillimanite is a better name, gemologically. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 23:49, 13 February 2007 (PST)<br />
:::For the project it might be best to cross reference to each other as both might be an option in a search. --[[User:Doos|Doos]] 10:08, 14 February 2007 (PST)<br />
* Very good. A cross reference will work well. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 13:17, 14 February 2007 (PST)<br />
==kyanite photograph==<br />
I don't know about anyone else, but this photo shows up with poor resolution on my monitor. There is an apparent lack of contrast with the dark background. Otherwise the stone looks very nice. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 18:47, 14 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Introduction_to_Gemology&diff=5718Talk:Introduction to Gemology2007-02-15T02:39:56Z<p>Tom Goodwin, G.G.: Introduction of the term "cachet" to describe attraction of certain gemstones.</p>
<hr />
<div>== quick draft ==<br />
<br />
This is just a quick draft of what it could look like, feel free to edit --[[User:Doos|Doos]] 12:44, 1 February 2006 (PST)<br />
<br />
:Shouldn't availability also be part of the "what makes a gemstone" section? Africanuck, March 8<br />
<br />
Yes that is a big part of it, but that is covered in "rarity". Although "availability" and "rarity" are usually the same factors, it may be artificial. Like the diamond cartel and probably also tanzanite. Furthermore politcs may play a role in this. For the most part this is not the case fortunatly. Feel free to define "rarity". --[[User:Doos|Doos]] 14:50, 8 March 2006 (PST)<br />
<br />
Ok, I pulled out my FGA stuff, what they list is acceptability (not availability, you are right that is rarity, silly me) but don't list price as a criteria.... You probably know more than I, but some of the stones that are considered gemstones are pretty cheap, and I'm not too clear on how price enter into it other than as a reflection of it's desirability (often dictated by fashion) and availability?<br />
<br />
One other question, is that supposed to be inorganic or organic? --[[User:Africanuck|Africanuck]] 06:51, 9 March 2006 (PST)<br />
<br />
:oops, organic ofcourse. You are right, let's drop "price". --[[User:Doos|Doos]] 07:16, 9 March 2006 (PST)<br />
<br />
changed inorganic to organic and changed price to acceptability --[[User:Africanuck|Africanuck]] 07:35, 9 March 2006 (PST)<br />
<br />
I'm also kind of wondering if "fashion" really fits in there... it's not really a criteria of whether or not a stone is a gem, and might be more appropriate to have it as part of the acceptability or rarity definitions. Or if we are going to touch on the subject of value, it might be added there. What do you think? --[[User:Africanuck|Africanuck]] 11:08, 10 March 2006 (PST)<br />
<br />
:Well fashion is a factor for much of the lower end gemstones (and at times for higher ends). If you look at the early 19th century you will find that lava stone was used widely in jewelry. Although we don't regard lava stone anything more than a curiousity in antique jewelry (studies showed that many of it was mere cement), it was used extensive in jewelry then (mainly due to the excavations of Pompeii and Herculanium). Painite is a new craze and might well be incorperated more a more into jewelry, also transforming it from a mineral into a gem. Ammolite is another example, it hardly passes the durability/rarity test. Yet many people seem to like it. So fashion plays a role. It's a thin line, a very thin one in many cases. --[[User:Doos|Doos]] 12:27, 10 March 2006 (PST)<br />
<br />
:Maybe acceptability/fashion .. I could feel comfortable with that. --[[User:Doos|Doos]] 12:32, 10 March 2006 (PST)<br />
*Antoinette Matlins uses the term "cachet" to describe the attraction that some gemstones convey in terms of "fashion." [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 18:39, 14 February 2007 (PST)<br />
== rollback ==<br />
<br />
Africa edited the Gem-A section and I tested the rollback .. so I needed to put her edits back by hand. Use 'rollback' with care so it seems.<br />
<br />
== AIGS section ==<br />
<br />
In the AIGS section, the following paragraphs are confusing to me. Any help on this?<br />
<br />
"The A.G. (Accredited Gemologist ) Diploma :<br />
<br />
The A.G. program includes the 4 core courses: E102: Gem Identification, E103: Diamond Grading and Pricing, E201: Colored Stone Grading and Pricing, E301: Synthetic and Treated Gem Identification.<br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthethics and Treated Gems”. "<br />
<br />
also, i think CGA should be added to educational institutes.<br />
<br />
: I can read it alright, but if it's confusing for you, then probably to others aswell.Is it the numbers that make it hard to read (eg. E102 etc)? I added the cga.--[[User:Doos|Doos]] 06:33, 28 February 2006 (PST)<br />
<br />
thanks for the CGA, doos. what confuses me about AIGS is the first line with the colon -- what does that refer to? to the following paragraphs? i see now that the last two really do link up fine (the paragraphing confused me but now i see it is ok). it is the first line that seems to be hanging in the wind, to me anyway.<br />
<br />
:I think that refers to the module codes of the courses. I didn't write that part so I dont really know. Rewrite it if you think that could be clearer.<br />
<br />
<br />
ok, did. check it out to see if i botched it.<br />
<br />
== tellsell ==<br />
<br />
under career opps, what is a "tellsell company"? [[User:Gemma|Gemma]] 20:35, 2 November 2006 (PST)<br />
: maybe that should read "telsell"? .. like JTV --[[User:Doos|Doos]] 07:13, 3 November 2006 (PST)<br />
<br />
that makes sense, thanks [[User:Gemma|Gemma]] 16:53, 3 November 2006 (PST)<br />
<br />
spell checked and edited [[User:Gemma|Gemma]] 20:19, 6 November 2006 (PST)<br />
<br />
== Definition of Gemologist ==<br />
A lot of people (like rockhounds) study gem minerals. Does that make them academically trained? When I think of anyone who is a "ologist" I think of formal academic training and achievement to attain such a title. In my opinion, because of this, the definition of "gemologist" needs to be edited and expanded here reflecting the professional full time work and dedication involved. I know a lot of amateur "gemologists" who couldn't separate glass from diamond. NO JOKE! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 17:32, 14 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Introduction_to_Gemology&diff=5717Introduction to Gemology2007-02-15T02:24:10Z<p>Tom Goodwin, G.G.: Edited 'Read" to understand.</p>
<hr />
<div>==General information on Gemology==<br />
<br />
===What is Gemology?===<br />
<br />
'''Gemology''' is the scientific study of gemstones, which often involves the study of mineralogical fundamentals such as formations, genesis, localities, physical properties and identification of gemstones. It includes the basic knowledge of structural, crystallographic, chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned.<br />
<br />
''Special Gemology'' deals with categories and varieties of gemstones, synthetic stones and imitations. Conventionally, the organic substances such as amber, pearls, coral and the non-minerals are also included in this subject of special gemology.<br />
<br />
''Practical Gemology'' refers to the application of the knowledge of characteristics and properties of gemstones in identification or separation of synthetics and imitations. Diamond grading is included in practical gemology.<br />
<br />
===What is a Gemologist?===<br />
<br />
A gemologist is someone who studies gemstones. Being recognized as a gemologist usually involves having credentials from one of the Institutes for Gem(m)ological Studies discussed below (see '''Becoming a Gemologist''' below).<br />
<br />
===What are gemstones?===<br />
<br />
Gemstones are usually [[mineral]]s but sometimes [[organic | <SPAN title=" derived from a living organism " class="popup">organic</SPAN>]] substances.<br />
What separates them from minerals in general is that they are used in jewelry or for ornamentation. That is a very thin line of separation, but usually we take 4 factors into account:<br />
<br />
* [[Durability]]<br />
* [[Rarity]]<br />
* [[Beauty]]<br />
* [[Acceptability]]<br />
<br />
And, of course, there is a 5th factor:<br />
<br />
* [[Fashion]] <br />
<br />
All the factors above are relative in nature. For instance, [[amber]] has very poor durability, isn't very rare and in general is not highly priced. Yet it is considered to be a gem due to its beauty.<br />
<br />
On the other hand, most [[sapphire]] has good durability but can be very unattractive and inexpensive. Only a small portion of all sapphires mined have good color/beauty. The same can be said for [[diamond]]; the vast majority of diamonds mined are used for industrial purposes because they lack the necessary beauty to be worn as jewelery.<br />
<br />
==Becoming a Gemologist==<br />
<br />
Becoming a gemologist in general means hard work and commitment. A wise teacher once said "You are only permitted to read books related to our trade and a religious book of your choice from now on . . . for the rest of your life".<br />
<br />
===Education===<br />
<br />
Although you can find very useful information on the Internet (like here), we '''strongly''' suggest that you take formal training from one of the established institutes listed below. Our editors have graduated from at least one of them.<br />
<br />
====Gem-A====<br />
<br />
Better known as The Gemmological Association and Gem Testing Laboratory of Great Britain, this school is London based with departments worldwide. It offers distance tutoring as well as teaching centers.<br><br />
The primary focus is on in-depth theory and the exams are the hardest to take in the industry. A fellowship of Gem-A means esteem. <br />
<br />
Costs:<br />
<br />
Foundation correspondence course GBP 993.00<br><br />
Diploma correspondence course GBP 1356.00 (on completion is granted the FGA title).<br />
<br />
Gem Diamond diploma course GBP 1584.00 (on completion is granted the DGA title).<br />
<br />
Website http://gem-a.info/<br />
<br />
====GIA====<br />
<br />
The Gemological Institute of America is the most prestigious and respected institute for gemology within the United States. Its main location is in Carlsbad, California, with facilities in New York and Los Angeles. Correspondence courses are available and encouraged. <br />
It was established in 1931, and currently the GIA is the world’s largest and one of the most respected nonprofit institutes of gemological research and learning internationally.<br />
It employs nearly 900, including scientists, diamond graders, and educators.<br />
<br />
Costs:<br />
<br />
On campus (CB/NY/LA): 6 month continuous program (780 hours) $13,995<br />
<br />
Distance Education: GEM130, GEM230, GEM230L, GEM120, GEM220,GEM220L, GEM240, GEM240L (Maximum completion time: 63 months) $6,975 ($7,395 International)<br />
<br />
What you earn: Graduate Gemologist Diploma, Graduate Diamonds Diploma, Graduate Colored Stones Diploma<br><br />
Website: http://www.gia.edu<br />
<br />
====AIGS====<br />
Thailand is in the heart of Southeast Asia's gem and jewelry production and trading area. It presents you with an extraordinary opportunity to learn gemology in theory and practice while experiencing the gem business in a three dimensional way. <br />
<br />
The A.G. program, which leads to the A.G. (Accredited Gemologist) Diploma, includes the four core courses:<br> <br />
:E102: Gem Identification<br><br />
:E103: Diamond Grading and Pricing<br><br />
:E201: Colored Stone Grading and Pricing<br><br />
:E301: Synthetic and Treated Gem Identification. <br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthetics and Treated Gems”. <br />
<br />
Students enrolling in the entire A.G. program are entitled to a 15% discount off the total tuition fee. Courses must be taken within one year of the first date of payment. Beyond the one year period, students will be subjected to any tuition increases that may have occurred. (Example: Old fee = 20,000 Baht, New fee in effect since date of enrollment = 22,000 Baht, Additional amount to be paid = 2,000 Baht.)<br />
<br />
Living expenses and general overhead are amazingly low compared to countries such as USA, Japan and most of Europe. Students studying at the AIGS can live with a US$600 to US$1000 budget per month including housing near the school, weekend field trips, restaurants and entertainment. Of course, you can spend much more if you want to, but this amount yields a comfortable lifestyle!<br><br />
Website: http://www.aigsthailand.com/<br />
<br />
====DGemG====<br />
The Deutsche Gemmologische Gesellschaft (The Educational Training Center of the German Gemmological Association) is located in Idar-Oberstein, Germany. Idar-Oberstein is an international colored stone gem capital, where gem cutting has been traditionally mastered for centuries. It is currently bustling with local gem artists and studios. It has, perhaps, the highest per capita population of gem cutters in the world! The German Gemmological Association was founded in 1932.<br />
Its laboratories have modern state of the art equipment, and one of the most extensive colored and exotic gemstone collections available.<br />
<br />
Costs:<br />
<br />
Euro 5,800.00 <br><br />
<br />
Website:http://www.dgemg.de/gemmologen_eng/index.php?seite=home<br />
<br />
====FGAA====<br />
<br />
The Gemmological Association of Australia (GAA), founded in 1945, is Australia’s historic trade-accepted non-profit educational authority for gemology. <br><br />
They offer gemological courses in 6 state divisions.<br />
<br />
Costs: contact one of the six state divisions for pricing.<br />
<br />
Website: [http://www.gem.org.au www.gem.org.au]<br />
<br />
====CGA====<br />
<br />
The Canadian Gemmological Association, based in Toronto Canada, is a Canada-wide professional organization which has set the standard for excellence in the practice of gemology. It was founded in 1958 by Dean S.M. Field, and has since provided training in gemology to persons dealing with gemstones in the jewelery industry and to hobbyists for better appreciation and possible new career opportunities within gemology.<br />
<br />
They offer a one-year correspondence course as well classes on location.<br />
<br />
Costs:<br />
<br />
The two-year correspondence course, leading to a Diploma in Gemmology and a Fellowship (FCGmA) in the Canadian Gemmological Association, is offered for CAD 2,020.00<br />
<br />
Website [http://www.canadiangemmological.com/ canadagemmological.com]<br />
<br />
===Post Graduate===<br />
<br />
After gaining your gemological diploma, the real fun starts. You will know the basics and more importantly you will know how to understand the many articles published in various [[periodicals]].<br><br />
If you keep up as a consumer of the gemological literature and are involved with continuing education, you will be a good gemologist one day.<br />
<br />
====Career Opportunities====<br />
<br />
As with any profession, it is all up to you what you will become and what your salary will be.<br />
<br />
Think of a gemological diploma as if you have finished your first year in college and the pay rate according to that when you start out. You will be qualified to find jobs in gemological laboratories worldwide and will be the key figure in the local jewelry store. You may become manager of a telsell company, start your own gem trading business, become an appraiser, or you might just stay shoveling municipal gardens etc. Anything you set your mind to. Pay rate is according to experience and market.<br /><br />
Our best advice is to start networking from the start and to seek a new employer every few years so you can gain as much know-how as you can.</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Introduction_to_Gemology&diff=5716Introduction to Gemology2007-02-15T01:57:04Z<p>Tom Goodwin, G.G.: Edited "Post Graduate" section to reflect consumption of gemological literature and continuing education.</p>
<hr />
<div>==General information on Gemology==<br />
<br />
===What is Gemology?===<br />
<br />
'''Gemology''' is the scientific study of gemstones, which often involves the study of mineralogical fundamentals such as formations, genesis, localities, physical properties and identification of gemstones. It includes the basic knowledge of structural, crystallographic, chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned.<br />
<br />
''Special Gemology'' deals with categories and varieties of gemstones, synthetic stones and imitations. Conventionally, the organic substances such as amber, pearls, coral and the non-minerals are also included in this subject of special gemology.<br />
<br />
''Practical Gemology'' refers to the application of the knowledge of characteristics and properties of gemstones in identification or separation of synthetics and imitations. Diamond grading is included in practical gemology.<br />
<br />
===What is a Gemologist?===<br />
<br />
A gemologist is someone who studies gemstones. Being recognized as a gemologist usually involves having credentials from one of the Institutes for Gem(m)ological Studies discussed below (see '''Becoming a Gemologist''' below).<br />
<br />
===What are gemstones?===<br />
<br />
Gemstones are usually [[mineral]]s but sometimes [[organic | <SPAN title=" derived from a living organism " class="popup">organic</SPAN>]] substances.<br />
What separates them from minerals in general is that they are used in jewelry or for ornamentation. That is a very thin line of separation, but usually we take 4 factors into account:<br />
<br />
* [[Durability]]<br />
* [[Rarity]]<br />
* [[Beauty]]<br />
* [[Acceptability]]<br />
<br />
And, of course, there is a 5th factor:<br />
<br />
* [[Fashion]] <br />
<br />
All the factors above are relative in nature. For instance, [[amber]] has very poor durability, isn't very rare and in general is not highly priced. Yet it is considered to be a gem due to its beauty.<br />
<br />
On the other hand, most [[sapphire]] has good durability but can be very unattractive and inexpensive. Only a small portion of all sapphires mined have good color/beauty. The same can be said for [[diamond]]; the vast majority of diamonds mined are used for industrial purposes because they lack the necessary beauty to be worn as jewelery.<br />
<br />
==Becoming a Gemologist==<br />
<br />
Becoming a gemologist in general means hard work and commitment. A wise teacher once said "You are only permitted to read books related to our trade and a religious book of your choice from now on . . . for the rest of your life".<br />
<br />
===Education===<br />
<br />
Although you can find very useful information on the Internet (like here), we '''strongly''' suggest that you take formal training from one of the established institutes listed below. Our editors have graduated from at least one of them.<br />
<br />
====Gem-A====<br />
<br />
Better known as The Gemmological Association and Gem Testing Laboratory of Great Britain, this school is London based with departments worldwide. It offers distance tutoring as well as teaching centers.<br><br />
The primary focus is on in-depth theory and the exams are the hardest to take in the industry. A fellowship of Gem-A means esteem. <br />
<br />
Costs:<br />
<br />
Foundation correspondence course GBP 993.00<br><br />
Diploma correspondence course GBP 1356.00 (on completion is granted the FGA title).<br />
<br />
Gem Diamond diploma course GBP 1584.00 (on completion is granted the DGA title).<br />
<br />
Website http://gem-a.info/<br />
<br />
====GIA====<br />
<br />
The Gemological Institute of America is the most prestigious and respected institute for gemology within the United States. Its main location is in Carlsbad, California, with facilities in New York and Los Angeles. Correspondence courses are available and encouraged. <br />
It was established in 1931, and currently the GIA is the world’s largest and one of the most respected nonprofit institutes of gemological research and learning internationally.<br />
It employs nearly 900, including scientists, diamond graders, and educators.<br />
<br />
Costs:<br />
<br />
On campus (CB/NY/LA): 6 month continuous program (780 hours) $13,995<br />
<br />
Distance Education: GEM130, GEM230, GEM230L, GEM120, GEM220,GEM220L, GEM240, GEM240L (Maximum completion time: 63 months) $6,975 ($7,395 International)<br />
<br />
What you earn: Graduate Gemologist Diploma, Graduate Diamonds Diploma, Graduate Colored Stones Diploma<br><br />
Website: http://www.gia.edu<br />
<br />
====AIGS====<br />
Thailand is in the heart of Southeast Asia's gem and jewelry production and trading area. It presents you with an extraordinary opportunity to learn gemology in theory and practice while experiencing the gem business in a three dimensional way. <br />
<br />
The A.G. program, which leads to the A.G. (Accredited Gemologist) Diploma, includes the four core courses:<br> <br />
:E102: Gem Identification<br><br />
:E103: Diamond Grading and Pricing<br><br />
:E201: Colored Stone Grading and Pricing<br><br />
:E301: Synthetic and Treated Gem Identification. <br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthetics and Treated Gems”. <br />
<br />
Students enrolling in the entire A.G. program are entitled to a 15% discount off the total tuition fee. Courses must be taken within one year of the first date of payment. Beyond the one year period, students will be subjected to any tuition increases that may have occurred. (Example: Old fee = 20,000 Baht, New fee in effect since date of enrollment = 22,000 Baht, Additional amount to be paid = 2,000 Baht.)<br />
<br />
Living expenses and general overhead are amazingly low compared to countries such as USA, Japan and most of Europe. Students studying at the AIGS can live with a US$600 to US$1000 budget per month including housing near the school, weekend field trips, restaurants and entertainment. Of course, you can spend much more if you want to, but this amount yields a comfortable lifestyle!<br><br />
Website: http://www.aigsthailand.com/<br />
<br />
====DGemG====<br />
The Deutsche Gemmologische Gesellschaft (The Educational Training Center of the German Gemmological Association) is located in Idar-Oberstein, Germany. Idar-Oberstein is an international colored stone gem capital, where gem cutting has been traditionally mastered for centuries. It is currently bustling with local gem artists and studios. It has, perhaps, the highest per capita population of gem cutters in the world! The German Gemmological Association was founded in 1932.<br />
Its laboratories have modern state of the art equipment, and one of the most extensive colored and exotic gemstone collections available.<br />
<br />
Costs:<br />
<br />
Euro 5,800.00 <br><br />
<br />
Website:http://www.dgemg.de/gemmologen_eng/index.php?seite=home<br />
<br />
====FGAA====<br />
<br />
The Gemmological Association of Australia (GAA), founded in 1945, is Australia’s historic trade-accepted non-profit educational authority for gemology. <br><br />
They offer gemological courses in 6 state divisions.<br />
<br />
Costs: contact one of the six state divisions for pricing.<br />
<br />
Website: [http://www.gem.org.au www.gem.org.au]<br />
<br />
====CGA====<br />
<br />
The Canadian Gemmological Association, based in Toronto Canada, is a Canada-wide professional organization which has set the standard for excellence in the practice of gemology. It was founded in 1958 by Dean S.M. Field, and has since provided training in gemology to persons dealing with gemstones in the jewelery industry and to hobbyists for better appreciation and possible new career opportunities within gemology.<br />
<br />
They offer a one-year correspondence course as well classes on location.<br />
<br />
Costs:<br />
<br />
The two-year correspondence course, leading to a Diploma in Gemmology and a Fellowship (FCGmA) in the Canadian Gemmological Association, is offered for CAD 2,020.00<br />
<br />
Website [http://www.canadiangemmological.com/ canadagemmological.com]<br />
<br />
===Post Graduate===<br />
<br />
After gaining your gemological diploma, the real fun starts. You will know the basics and more importantly you will know how to read the many articles published in various [[periodicals]].<br><br />
If you keep up as a consumer of the gemological literature and are involved with continuing education, you will be a good gemologist one day.<br />
<br />
====Career Opportunities====<br />
<br />
As with any profession, it is all up to you what you will become and what your salary will be.<br />
<br />
Think of a gemological diploma as if you have finished your first year in college and the pay rate according to that when you start out. You will be qualified to find jobs in gemological laboratories worldwide and will be the key figure in the local jewelry store. You may become manager of a telsell company, start your own gem trading business, become an appraiser, or you might just stay shoveling municipal gardens etc. Anything you set your mind to. Pay rate is according to experience and market.<br /><br />
Our best advice is to start networking from the start and to seek a new employer every few years so you can gain as much know-how as you can.</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Introduction_to_Gemology&diff=5715Introduction to Gemology2007-02-15T01:50:13Z<p>Tom Goodwin, G.G.: Edited "Housing" for "Lodging"</p>
<hr />
<div>==General information on Gemology==<br />
<br />
===What is Gemology?===<br />
<br />
'''Gemology''' is the scientific study of gemstones, which often involves the study of mineralogical fundamentals such as formations, genesis, localities, physical properties and identification of gemstones. It includes the basic knowledge of structural, crystallographic, chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned.<br />
<br />
''Special Gemology'' deals with categories and varieties of gemstones, synthetic stones and imitations. Conventionally, the organic substances such as amber, pearls, coral and the non-minerals are also included in this subject of special gemology.<br />
<br />
''Practical Gemology'' refers to the application of the knowledge of characteristics and properties of gemstones in identification or separation of synthetics and imitations. Diamond grading is included in practical gemology.<br />
<br />
===What is a Gemologist?===<br />
<br />
A gemologist is someone who studies gemstones. Being recognized as a gemologist usually involves having credentials from one of the Institutes for Gem(m)ological Studies discussed below (see '''Becoming a Gemologist''' below).<br />
<br />
===What are gemstones?===<br />
<br />
Gemstones are usually [[mineral]]s but sometimes [[organic | <SPAN title=" derived from a living organism " class="popup">organic</SPAN>]] substances.<br />
What separates them from minerals in general is that they are used in jewelry or for ornamentation. That is a very thin line of separation, but usually we take 4 factors into account:<br />
<br />
* [[Durability]]<br />
* [[Rarity]]<br />
* [[Beauty]]<br />
* [[Acceptability]]<br />
<br />
And, of course, there is a 5th factor:<br />
<br />
* [[Fashion]] <br />
<br />
All the factors above are relative in nature. For instance, [[amber]] has very poor durability, isn't very rare and in general is not highly priced. Yet it is considered to be a gem due to its beauty.<br />
<br />
On the other hand, most [[sapphire]] has good durability but can be very unattractive and inexpensive. Only a small portion of all sapphires mined have good color/beauty. The same can be said for [[diamond]]; the vast majority of diamonds mined are used for industrial purposes because they lack the necessary beauty to be worn as jewelery.<br />
<br />
==Becoming a Gemologist==<br />
<br />
Becoming a gemologist in general means hard work and commitment. A wise teacher once said "You are only permitted to read books related to our trade and a religious book of your choice from now on . . . for the rest of your life".<br />
<br />
===Education===<br />
<br />
Although you can find very useful information on the Internet (like here), we '''strongly''' suggest that you take formal training from one of the established institutes listed below. Our editors have graduated from at least one of them.<br />
<br />
====Gem-A====<br />
<br />
Better known as The Gemmological Association and Gem Testing Laboratory of Great Britain, this school is London based with departments worldwide. It offers distance tutoring as well as teaching centers.<br><br />
The primary focus is on in-depth theory and the exams are the hardest to take in the industry. A fellowship of Gem-A means esteem. <br />
<br />
Costs:<br />
<br />
Foundation correspondence course GBP 993.00<br><br />
Diploma correspondence course GBP 1356.00 (on completion is granted the FGA title).<br />
<br />
Gem Diamond diploma course GBP 1584.00 (on completion is granted the DGA title).<br />
<br />
Website http://gem-a.info/<br />
<br />
====GIA====<br />
<br />
The Gemological Institute of America is the most prestigious and respected institute for gemology within the United States. Its main location is in Carlsbad, California, with facilities in New York and Los Angeles. Correspondence courses are available and encouraged. <br />
It was established in 1931, and currently the GIA is the world’s largest and one of the most respected nonprofit institutes of gemological research and learning internationally.<br />
It employs nearly 900, including scientists, diamond graders, and educators.<br />
<br />
Costs:<br />
<br />
On campus (CB/NY/LA): 6 month continuous program (780 hours) $13,995<br />
<br />
Distance Education: GEM130, GEM230, GEM230L, GEM120, GEM220,GEM220L, GEM240, GEM240L (Maximum completion time: 63 months) $6,975 ($7,395 International)<br />
<br />
What you earn: Graduate Gemologist Diploma, Graduate Diamonds Diploma, Graduate Colored Stones Diploma<br><br />
Website: http://www.gia.edu<br />
<br />
====AIGS====<br />
Thailand is in the heart of Southeast Asia's gem and jewelry production and trading area. It presents you with an extraordinary opportunity to learn gemology in theory and practice while experiencing the gem business in a three dimensional way. <br />
<br />
The A.G. program, which leads to the A.G. (Accredited Gemologist) Diploma, includes the four core courses:<br> <br />
:E102: Gem Identification<br><br />
:E103: Diamond Grading and Pricing<br><br />
:E201: Colored Stone Grading and Pricing<br><br />
:E301: Synthetic and Treated Gem Identification. <br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthetics and Treated Gems”. <br />
<br />
Students enrolling in the entire A.G. program are entitled to a 15% discount off the total tuition fee. Courses must be taken within one year of the first date of payment. Beyond the one year period, students will be subjected to any tuition increases that may have occurred. (Example: Old fee = 20,000 Baht, New fee in effect since date of enrollment = 22,000 Baht, Additional amount to be paid = 2,000 Baht.)<br />
<br />
Living expenses and general overhead are amazingly low compared to countries such as USA, Japan and most of Europe. Students studying at the AIGS can live with a US$600 to US$1000 budget per month including housing near the school, weekend field trips, restaurants and entertainment. Of course, you can spend much more if you want to, but this amount yields a comfortable lifestyle!<br><br />
Website: http://www.aigsthailand.com/<br />
<br />
====DGemG====<br />
The Deutsche Gemmologische Gesellschaft (The Educational Training Center of the German Gemmological Association) is located in Idar-Oberstein, Germany. Idar-Oberstein is an international colored stone gem capital, where gem cutting has been traditionally mastered for centuries. It is currently bustling with local gem artists and studios. It has, perhaps, the highest per capita population of gem cutters in the world! The German Gemmological Association was founded in 1932.<br />
Its laboratories have modern state of the art equipment, and one of the most extensive colored and exotic gemstone collections available.<br />
<br />
Costs:<br />
<br />
Euro 5,800.00 <br><br />
<br />
Website:http://www.dgemg.de/gemmologen_eng/index.php?seite=home<br />
<br />
====FGAA====<br />
<br />
The Gemmological Association of Australia (GAA), founded in 1945, is Australia’s historic trade-accepted non-profit educational authority for gemology. <br><br />
They offer gemological courses in 6 state divisions.<br />
<br />
Costs: contact one of the six state divisions for pricing.<br />
<br />
Website: [http://www.gem.org.au www.gem.org.au]<br />
<br />
====CGA====<br />
<br />
The Canadian Gemmological Association, based in Toronto Canada, is a Canada-wide professional organization which has set the standard for excellence in the practice of gemology. It was founded in 1958 by Dean S.M. Field, and has since provided training in gemology to persons dealing with gemstones in the jewelery industry and to hobbyists for better appreciation and possible new career opportunities within gemology.<br />
<br />
They offer a one-year correspondence course as well classes on location.<br />
<br />
Costs:<br />
<br />
The two-year correspondence course, leading to a Diploma in Gemmology and a Fellowship (FCGmA) in the Canadian Gemmological Association, is offered for CAD 2,020.00<br />
<br />
Website [http://www.canadiangemmological.com/ canadagemmological.com]<br />
<br />
===Post Graduate===<br />
<br />
After gaining your gemological diploma, the real fun starts. You will know the basics and more importantly you will know how to read the many articles published in various [[periodicals]].<br><br />
If you keep up to date and involved, you will be a good gemologist one day.<br />
<br />
====Career Opportunities====<br />
<br />
As with any profession, it is all up to you what you will become and what your salary will be.<br />
<br />
Think of a gemological diploma as if you have finished your first year in college and the pay rate according to that when you start out. You will be qualified to find jobs in gemological laboratories worldwide and will be the key figure in the local jewelry store. You may become manager of a telsell company, start your own gem trading business, become an appraiser, or you might just stay shoveling municipal gardens etc. Anything you set your mind to. Pay rate is according to experience and market.<br /><br />
Our best advice is to start networking from the start and to seek a new employer every few years so you can gain as much know-how as you can.</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Introduction_to_Gemology&diff=5714Introduction to Gemology2007-02-15T01:46:57Z<p>Tom Goodwin, G.G.: Edited the word "cheap" --->inexpensive</p>
<hr />
<div>==General information on Gemology==<br />
<br />
===What is Gemology?===<br />
<br />
'''Gemology''' is the scientific study of gemstones, which often involves the study of mineralogical fundamentals such as formations, genesis, localities, physical properties and identification of gemstones. It includes the basic knowledge of structural, crystallographic, chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned.<br />
<br />
''Special Gemology'' deals with categories and varieties of gemstones, synthetic stones and imitations. Conventionally, the organic substances such as amber, pearls, coral and the non-minerals are also included in this subject of special gemology.<br />
<br />
''Practical Gemology'' refers to the application of the knowledge of characteristics and properties of gemstones in identification or separation of synthetics and imitations. Diamond grading is included in practical gemology.<br />
<br />
===What is a Gemologist?===<br />
<br />
A gemologist is someone who studies gemstones. Being recognized as a gemologist usually involves having credentials from one of the Institutes for Gem(m)ological Studies discussed below (see '''Becoming a Gemologist''' below).<br />
<br />
===What are gemstones?===<br />
<br />
Gemstones are usually [[mineral]]s but sometimes [[organic | <SPAN title=" derived from a living organism " class="popup">organic</SPAN>]] substances.<br />
What separates them from minerals in general is that they are used in jewelry or for ornamentation. That is a very thin line of separation, but usually we take 4 factors into account:<br />
<br />
* [[Durability]]<br />
* [[Rarity]]<br />
* [[Beauty]]<br />
* [[Acceptability]]<br />
<br />
And, of course, there is a 5th factor:<br />
<br />
* [[Fashion]] <br />
<br />
All the factors above are relative in nature. For instance, [[amber]] has very poor durability, isn't very rare and in general is not highly priced. Yet it is considered to be a gem due to its beauty.<br />
<br />
On the other hand, most [[sapphire]] has good durability but can be very unattractive and inexpensive. Only a small portion of all sapphires mined have good color/beauty. The same can be said for [[diamond]]; the vast majority of diamonds mined are used for industrial purposes because they lack the necessary beauty to be worn as jewelery.<br />
<br />
==Becoming a Gemologist==<br />
<br />
Becoming a gemologist in general means hard work and commitment. A wise teacher once said "You are only permitted to read books related to our trade and a religious book of your choice from now on . . . for the rest of your life".<br />
<br />
===Education===<br />
<br />
Although you can find very useful information on the Internet (like here), we '''strongly''' suggest that you take formal training from one of the established institutes listed below. Our editors have graduated from at least one of them.<br />
<br />
====Gem-A====<br />
<br />
Better known as The Gemmological Association and Gem Testing Laboratory of Great Britain, this school is London based with departments worldwide. It offers distance tutoring as well as teaching centers.<br><br />
The primary focus is on in-depth theory and the exams are the hardest to take in the industry. A fellowship of Gem-A means esteem. <br />
<br />
Costs:<br />
<br />
Foundation correspondence course GBP 993.00<br><br />
Diploma correspondence course GBP 1356.00 (on completion is granted the FGA title).<br />
<br />
Gem Diamond diploma course GBP 1584.00 (on completion is granted the DGA title).<br />
<br />
Website http://gem-a.info/<br />
<br />
====GIA====<br />
<br />
The Gemological Institute of America is the most prestigious and respected institute for gemology within the United States. Its main location is in Carlsbad, California, with facilities in New York and Los Angeles. Correspondence courses are available and encouraged. <br />
It was established in 1931, and currently the GIA is the world’s largest and one of the most respected nonprofit institutes of gemological research and learning internationally.<br />
It employs nearly 900, including scientists, diamond graders, and educators.<br />
<br />
Costs:<br />
<br />
On campus (CB/NY/LA): 6 month continuous program (780 hours) $13,995<br />
<br />
Distance Education: GEM130, GEM230, GEM230L, GEM120, GEM220,GEM220L, GEM240, GEM240L (Maximum completion time: 63 months) $6,975 ($7,395 International)<br />
<br />
What you earn: Graduate Gemologist Diploma, Graduate Diamonds Diploma, Graduate Colored Stones Diploma<br><br />
Website: http://www.gia.edu<br />
<br />
====AIGS====<br />
Thailand is in the heart of Southeast Asia's gem and jewelry production and trading area. It presents you with an extraordinary opportunity to learn gemology in theory and practice while experiencing the gem business in a three dimensional way. <br />
<br />
The A.G. program, which leads to the A.G. (Accredited Gemologist) Diploma, includes the four core courses:<br> <br />
:E102: Gem Identification<br><br />
:E103: Diamond Grading and Pricing<br><br />
:E201: Colored Stone Grading and Pricing<br><br />
:E301: Synthetic and Treated Gem Identification. <br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthetics and Treated Gems”. <br />
<br />
Students enrolling in the entire A.G. program are entitled to a 15% discount off the total tuition fee. Courses must be taken within one year of the first date of payment. Beyond the one year period, students will be subjected to any tuition increases that may have occurred. (Example: Old fee = 20,000 Baht, New fee in effect since date of enrollment = 22,000 Baht, Additional amount to be paid = 2,000 Baht.)<br />
<br />
Living expenses and general overhead are amazingly low compared to countries such as USA, Japan and most of Europe. Students studying at the AIGS can live with a US$600 to US$1000 budget per month including lodging near the school, weekend field trips, restaurants and entertainment. Of course, you can spend much more if you want to, but this amount yields a comfortable lifestyle!<br><br />
Website: http://www.aigsthailand.com/<br />
<br />
====DGemG====<br />
The Deutsche Gemmologische Gesellschaft (The Educational Training Center of the German Gemmological Association) is located in Idar-Oberstein, Germany. Idar-Oberstein is an international colored stone gem capital, where gem cutting has been traditionally mastered for centuries. It is currently bustling with local gem artists and studios. It has, perhaps, the highest per capita population of gem cutters in the world! The German Gemmological Association was founded in 1932.<br />
Its laboratories have modern state of the art equipment, and one of the most extensive colored and exotic gemstone collections available.<br />
<br />
Costs:<br />
<br />
Euro 5,800.00 <br><br />
<br />
Website:http://www.dgemg.de/gemmologen_eng/index.php?seite=home<br />
<br />
====FGAA====<br />
<br />
The Gemmological Association of Australia (GAA), founded in 1945, is Australia’s historic trade-accepted non-profit educational authority for gemology. <br><br />
They offer gemological courses in 6 state divisions.<br />
<br />
Costs: contact one of the six state divisions for pricing.<br />
<br />
Website: [http://www.gem.org.au www.gem.org.au]<br />
<br />
====CGA====<br />
<br />
The Canadian Gemmological Association, based in Toronto Canada, is a Canada-wide professional organization which has set the standard for excellence in the practice of gemology. It was founded in 1958 by Dean S.M. Field, and has since provided training in gemology to persons dealing with gemstones in the jewelery industry and to hobbyists for better appreciation and possible new career opportunities within gemology.<br />
<br />
They offer a one-year correspondence course as well classes on location.<br />
<br />
Costs:<br />
<br />
The two-year correspondence course, leading to a Diploma in Gemmology and a Fellowship (FCGmA) in the Canadian Gemmological Association, is offered for CAD 2,020.00<br />
<br />
Website [http://www.canadiangemmological.com/ canadagemmological.com]<br />
<br />
===Post Graduate===<br />
<br />
After gaining your gemological diploma, the real fun starts. You will know the basics and more importantly you will know how to read the many articles published in various [[periodicals]].<br><br />
If you keep up to date and involved, you will be a good gemologist one day.<br />
<br />
====Career Opportunities====<br />
<br />
As with any profession, it is all up to you what you will become and what your salary will be.<br />
<br />
Think of a gemological diploma as if you have finished your first year in college and the pay rate according to that when you start out. You will be qualified to find jobs in gemological laboratories worldwide and will be the key figure in the local jewelry store. You may become manager of a telsell company, start your own gem trading business, become an appraiser, or you might just stay shoveling municipal gardens etc. Anything you set your mind to. Pay rate is according to experience and market.<br /><br />
Our best advice is to start networking from the start and to seek a new employer every few years so you can gain as much know-how as you can.</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Introduction_to_Gemology&diff=5713Introduction to Gemology2007-02-15T01:44:52Z<p>Tom Goodwin, G.G.: Edited in "relative in nature" for "very subjective"</p>
<hr />
<div>==General information on Gemology==<br />
<br />
===What is Gemology?===<br />
<br />
'''Gemology''' is the scientific study of gemstones, which often involves the study of mineralogical fundamentals such as formations, genesis, localities, physical properties and identification of gemstones. It includes the basic knowledge of structural, crystallographic, chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned.<br />
<br />
''Special Gemology'' deals with categories and varieties of gemstones, synthetic stones and imitations. Conventionally, the organic substances such as amber, pearls, coral and the non-minerals are also included in this subject of special gemology.<br />
<br />
''Practical Gemology'' refers to the application of the knowledge of characteristics and properties of gemstones in identification or separation of synthetics and imitations. Diamond grading is included in practical gemology.<br />
<br />
===What is a Gemologist?===<br />
<br />
A gemologist is someone who studies gemstones. Being recognized as a gemologist usually involves having credentials from one of the Institutes for Gem(m)ological Studies discussed below (see '''Becoming a Gemologist''' below).<br />
<br />
===What are gemstones?===<br />
<br />
Gemstones are usually [[mineral]]s but sometimes [[organic | <SPAN title=" derived from a living organism " class="popup">organic</SPAN>]] substances.<br />
What separates them from minerals in general is that they are used in jewelry or for ornamentation. That is a very thin line of separation, but usually we take 4 factors into account:<br />
<br />
* [[Durability]]<br />
* [[Rarity]]<br />
* [[Beauty]]<br />
* [[Acceptability]]<br />
<br />
And, of course, there is a 5th factor:<br />
<br />
* [[Fashion]] <br />
<br />
All the factors above are relative in nature. For instance, [[amber]] has very poor durability, isn't very rare and in general is not highly priced. Yet it is considered to be a gem due to its beauty.<br />
<br />
On the other hand, most [[sapphire]] has good durability but can be very unattractive and cheap. Only a small portion of all sapphires mined have good color/beauty. The same can be said for [[diamond]]; the vast majority of diamonds mined are used for industrial purposes because they lack the necessary beauty to be worn as jewelery.<br />
<br />
==Becoming a Gemologist==<br />
<br />
Becoming a gemologist in general means hard work and commitment. A wise teacher once said "You are only permitted to read books related to our trade and a religious book of your choice from now on . . . for the rest of your life".<br />
<br />
===Education===<br />
<br />
Although you can find very useful information on the Internet (like here), we '''strongly''' suggest that you take formal training from one of the established institutes listed below. Our editors have graduated from at least one of them.<br />
<br />
====Gem-A====<br />
<br />
Better known as The Gemmological Association and Gem Testing Laboratory of Great Britain, this school is London based with departments worldwide. It offers distance tutoring as well as teaching centers.<br><br />
The primary focus is on in-depth theory and the exams are the hardest to take in the industry. A fellowship of Gem-A means esteem. <br />
<br />
Costs:<br />
<br />
Foundation correspondence course GBP 993.00<br><br />
Diploma correspondence course GBP 1356.00 (on completion is granted the FGA title).<br />
<br />
Gem Diamond diploma course GBP 1584.00 (on completion is granted the DGA title).<br />
<br />
Website http://gem-a.info/<br />
<br />
====GIA====<br />
<br />
The Gemological Institute of America is the most prestigious and respected institute for gemology within the United States. Its main location is in Carlsbad, California, with facilities in New York and Los Angeles. Correspondence courses are available and encouraged. <br />
It was established in 1931, and currently the GIA is the world’s largest and one of the most respected nonprofit institutes of gemological research and learning internationally.<br />
It employs nearly 900, including scientists, diamond graders, and educators.<br />
<br />
Costs:<br />
<br />
On campus (CB/NY/LA): 6 month continuous program (780 hours) $13,995<br />
<br />
Distance Education: GEM130, GEM230, GEM230L, GEM120, GEM220,GEM220L, GEM240, GEM240L (Maximum completion time: 63 months) $6,975 ($7,395 International)<br />
<br />
What you earn: Graduate Gemologist Diploma, Graduate Diamonds Diploma, Graduate Colored Stones Diploma<br><br />
Website: http://www.gia.edu<br />
<br />
====AIGS====<br />
Thailand is in the heart of Southeast Asia's gem and jewelry production and trading area. It presents you with an extraordinary opportunity to learn gemology in theory and practice while experiencing the gem business in a three dimensional way. <br />
<br />
The A.G. program, which leads to the A.G. (Accredited Gemologist) Diploma, includes the four core courses:<br> <br />
:E102: Gem Identification<br><br />
:E103: Diamond Grading and Pricing<br><br />
:E201: Colored Stone Grading and Pricing<br><br />
:E301: Synthetic and Treated Gem Identification. <br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthetics and Treated Gems”. <br />
<br />
Students enrolling in the entire A.G. program are entitled to a 15% discount off the total tuition fee. Courses must be taken within one year of the first date of payment. Beyond the one year period, students will be subjected to any tuition increases that may have occurred. (Example: Old fee = 20,000 Baht, New fee in effect since date of enrollment = 22,000 Baht, Additional amount to be paid = 2,000 Baht.)<br />
<br />
Living expenses and general overhead are amazingly low compared to countries such as USA, Japan and most of Europe. Students studying at the AIGS can live with a US$600 to US$1000 budget per month including lodging near the school, weekend field trips, restaurants and entertainment. Of course, you can spend much more if you want to, but this amount yields a comfortable lifestyle!<br><br />
Website: http://www.aigsthailand.com/<br />
<br />
====DGemG====<br />
The Deutsche Gemmologische Gesellschaft (The Educational Training Center of the German Gemmological Association) is located in Idar-Oberstein, Germany. Idar-Oberstein is an international colored stone gem capital, where gem cutting has been traditionally mastered for centuries. It is currently bustling with local gem artists and studios. It has, perhaps, the highest per capita population of gem cutters in the world! The German Gemmological Association was founded in 1932.<br />
Its laboratories have modern state of the art equipment, and one of the most extensive colored and exotic gemstone collections available.<br />
<br />
Costs:<br />
<br />
Euro 5,800.00 <br><br />
<br />
Website:http://www.dgemg.de/gemmologen_eng/index.php?seite=home<br />
<br />
====FGAA====<br />
<br />
The Gemmological Association of Australia (GAA), founded in 1945, is Australia’s historic trade-accepted non-profit educational authority for gemology. <br><br />
They offer gemological courses in 6 state divisions.<br />
<br />
Costs: contact one of the six state divisions for pricing.<br />
<br />
Website: [http://www.gem.org.au www.gem.org.au]<br />
<br />
====CGA====<br />
<br />
The Canadian Gemmological Association, based in Toronto Canada, is a Canada-wide professional organization which has set the standard for excellence in the practice of gemology. It was founded in 1958 by Dean S.M. Field, and has since provided training in gemology to persons dealing with gemstones in the jewelery industry and to hobbyists for better appreciation and possible new career opportunities within gemology.<br />
<br />
They offer a one-year correspondence course as well classes on location.<br />
<br />
Costs:<br />
<br />
The two-year correspondence course, leading to a Diploma in Gemmology and a Fellowship (FCGmA) in the Canadian Gemmological Association, is offered for CAD 2,020.00<br />
<br />
Website [http://www.canadiangemmological.com/ canadagemmological.com]<br />
<br />
===Post Graduate===<br />
<br />
After gaining your gemological diploma, the real fun starts. You will know the basics and more importantly you will know how to read the many articles published in various [[periodicals]].<br><br />
If you keep up to date and involved, you will be a good gemologist one day.<br />
<br />
====Career Opportunities====<br />
<br />
As with any profession, it is all up to you what you will become and what your salary will be.<br />
<br />
Think of a gemological diploma as if you have finished your first year in college and the pay rate according to that when you start out. You will be qualified to find jobs in gemological laboratories worldwide and will be the key figure in the local jewelry store. You may become manager of a telsell company, start your own gem trading business, become an appraiser, or you might just stay shoveling municipal gardens etc. Anything you set your mind to. Pay rate is according to experience and market.<br /><br />
Our best advice is to start networking from the start and to seek a new employer every few years so you can gain as much know-how as you can.</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Introduction_to_Gemology&diff=5712Introduction to Gemology2007-02-15T01:42:11Z<p>Tom Goodwin, G.G.: Edited "Our best advice"....</p>
<hr />
<div>==General information on Gemology==<br />
<br />
===What is Gemology?===<br />
<br />
'''Gemology''' is the scientific study of gemstones, which often involves the study of mineralogical fundamentals such as formations, genesis, localities, physical properties and identification of gemstones. It includes the basic knowledge of structural, crystallographic, chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned.<br />
<br />
''Special Gemology'' deals with categories and varieties of gemstones, synthetic stones and imitations. Conventionally, the organic substances such as amber, pearls, coral and the non-minerals are also included in this subject of special gemology.<br />
<br />
''Practical Gemology'' refers to the application of the knowledge of characteristics and properties of gemstones in identification or separation of synthetics and imitations. Diamond grading is included in practical gemology.<br />
<br />
===What is a Gemologist?===<br />
<br />
A gemologist is someone who studies gemstones. Being recognized as a gemologist usually involves having credentials from one of the Institutes for Gem(m)ological Studies discussed below (see '''Becoming a Gemologist''' below).<br />
<br />
===What are gemstones?===<br />
<br />
Gemstones are usually [[mineral]]s but sometimes [[organic | <SPAN title=" derived from a living organism " class="popup">organic</SPAN>]] substances.<br />
What separates them from minerals in general is that they are used in jewelry or for ornamentation. That is a very thin line of separation, but usually we take 4 factors into account:<br />
<br />
* [[Durability]]<br />
* [[Rarity]]<br />
* [[Beauty]]<br />
* [[Acceptability]]<br />
<br />
And, of course, there is a 5th factor:<br />
<br />
* [[Fashion]] <br />
<br />
All the factors above are very subjective. For instance, [[amber]] has very poor durability, isn't very rare and in general is not highly priced. Yet it is considered to be a gem due to its beauty.<br />
<br />
On the other hand, most [[sapphire]] has good durability but can be very unattractive and cheap. Only a small portion of all sapphires mined have good color/beauty. The same can be said for [[diamond]]; the vast majority of diamonds mined are used for industrial purposes because they lack the necessary beauty to be worn as jewelery.<br />
<br />
==Becoming a Gemologist==<br />
<br />
Becoming a gemologist in general means hard work and commitment. A wise teacher once said "You are only permitted to read books related to our trade and a religious book of your choice from now on . . . for the rest of your life".<br />
<br />
===Education===<br />
<br />
Although you can find very useful information on the Internet (like here), we '''strongly''' suggest that you take formal training from one of the established institutes listed below. Our editors have graduated from at least one of them.<br />
<br />
====Gem-A====<br />
<br />
Better known as The Gemmological Association and Gem Testing Laboratory of Great Britain, this school is London based with departments worldwide. It offers distance tutoring as well as teaching centers.<br><br />
The primary focus is on in-depth theory and the exams are the hardest to take in the industry. A fellowship of Gem-A means esteem. <br />
<br />
Costs:<br />
<br />
Foundation correspondence course GBP 993.00<br><br />
Diploma correspondence course GBP 1356.00 (on completion is granted the FGA title).<br />
<br />
Gem Diamond diploma course GBP 1584.00 (on completion is granted the DGA title).<br />
<br />
Website http://gem-a.info/<br />
<br />
====GIA====<br />
<br />
The Gemological Institute of America is the most prestigious and respected institute for gemology within the United States. Its main location is in Carlsbad, California, with facilities in New York and Los Angeles. Correspondence courses are available and encouraged. <br />
It was established in 1931, and currently the GIA is the world’s largest and one of the most respected nonprofit institutes of gemological research and learning internationally.<br />
It employs nearly 900, including scientists, diamond graders, and educators.<br />
<br />
Costs:<br />
<br />
On campus (CB/NY/LA): 6 month continuous program (780 hours) $13,995<br />
<br />
Distance Education: GEM130, GEM230, GEM230L, GEM120, GEM220,GEM220L, GEM240, GEM240L (Maximum completion time: 63 months) $6,975 ($7,395 International)<br />
<br />
What you earn: Graduate Gemologist Diploma, Graduate Diamonds Diploma, Graduate Colored Stones Diploma<br><br />
Website: http://www.gia.edu<br />
<br />
====AIGS====<br />
Thailand is in the heart of Southeast Asia's gem and jewelry production and trading area. It presents you with an extraordinary opportunity to learn gemology in theory and practice while experiencing the gem business in a three dimensional way. <br />
<br />
The A.G. program, which leads to the A.G. (Accredited Gemologist) Diploma, includes the four core courses:<br> <br />
:E102: Gem Identification<br><br />
:E103: Diamond Grading and Pricing<br><br />
:E201: Colored Stone Grading and Pricing<br><br />
:E301: Synthetic and Treated Gem Identification. <br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthetics and Treated Gems”. <br />
<br />
Students enrolling in the entire A.G. program are entitled to a 15% discount off the total tuition fee. Courses must be taken within one year of the first date of payment. Beyond the one year period, students will be subjected to any tuition increases that may have occurred. (Example: Old fee = 20,000 Baht, New fee in effect since date of enrollment = 22,000 Baht, Additional amount to be paid = 2,000 Baht.)<br />
<br />
Living expenses and general overhead are amazingly low compared to countries such as USA, Japan and most of Europe. Students studying at the AIGS can live with a US$600 to US$1000 budget per month including lodging near the school, weekend field trips, restaurants and entertainment. Of course, you can spend much more if you want to, but this amount yields a comfortable lifestyle!<br><br />
Website: http://www.aigsthailand.com/<br />
<br />
====DGemG====<br />
The Deutsche Gemmologische Gesellschaft (The Educational Training Center of the German Gemmological Association) is located in Idar-Oberstein, Germany. Idar-Oberstein is an international colored stone gem capital, where gem cutting has been traditionally mastered for centuries. It is currently bustling with local gem artists and studios. It has, perhaps, the highest per capita population of gem cutters in the world! The German Gemmological Association was founded in 1932.<br />
Its laboratories have modern state of the art equipment, and one of the most extensive colored and exotic gemstone collections available.<br />
<br />
Costs:<br />
<br />
Euro 5,800.00 <br><br />
<br />
Website:http://www.dgemg.de/gemmologen_eng/index.php?seite=home<br />
<br />
====FGAA====<br />
<br />
The Gemmological Association of Australia (GAA), founded in 1945, is Australia’s historic trade-accepted non-profit educational authority for gemology. <br><br />
They offer gemological courses in 6 state divisions.<br />
<br />
Costs: contact one of the six state divisions for pricing.<br />
<br />
Website: [http://www.gem.org.au www.gem.org.au]<br />
<br />
====CGA====<br />
<br />
The Canadian Gemmological Association, based in Toronto Canada, is a Canada-wide professional organization which has set the standard for excellence in the practice of gemology. It was founded in 1958 by Dean S.M. Field, and has since provided training in gemology to persons dealing with gemstones in the jewelery industry and to hobbyists for better appreciation and possible new career opportunities within gemology.<br />
<br />
They offer a one-year correspondence course as well classes on location.<br />
<br />
Costs:<br />
<br />
The two-year correspondence course, leading to a Diploma in Gemmology and a Fellowship (FCGmA) in the Canadian Gemmological Association, is offered for CAD 2,020.00<br />
<br />
Website [http://www.canadiangemmological.com/ canadagemmological.com]<br />
<br />
===Post Graduate===<br />
<br />
After gaining your gemological diploma, the real fun starts. You will know the basics and more importantly you will know how to read the many articles published in various [[periodicals]].<br><br />
If you keep up to date and involved, you will be a good gemologist one day.<br />
<br />
====Career Opportunities====<br />
<br />
As with any profession, it is all up to you what you will become and what your salary will be.<br />
<br />
Think of a gemological diploma as if you have finished your first year in college and the pay rate according to that when you start out. You will be qualified to find jobs in gemological laboratories worldwide and will be the key figure in the local jewelry store. You may become manager of a telsell company, start your own gem trading business, become an appraiser, or you might just stay shoveling municipal gardens etc. Anything you set your mind to. Pay rate is according to experience and market.<br /><br />
Our best advice is to start networking from the start and to seek a new employer every few years so you can gain as much know-how as you can.</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Introduction_to_Gemology&diff=5711Introduction to Gemology2007-02-15T01:39:53Z<p>Tom Goodwin, G.G.: Added question marks.</p>
<hr />
<div>==General information on Gemology==<br />
<br />
===What is Gemology?===<br />
<br />
'''Gemology''' is the scientific study of gemstones, which often involves the study of mineralogical fundamentals such as formations, genesis, localities, physical properties and identification of gemstones. It includes the basic knowledge of structural, crystallographic, chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned.<br />
<br />
''Special Gemology'' deals with categories and varieties of gemstones, synthetic stones and imitations. Conventionally, the organic substances such as amber, pearls, coral and the non-minerals are also included in this subject of special gemology.<br />
<br />
''Practical Gemology'' refers to the application of the knowledge of characteristics and properties of gemstones in identification or separation of synthetics and imitations. Diamond grading is included in practical gemology.<br />
<br />
===What is a Gemologist?===<br />
<br />
A gemologist is someone who studies gemstones. Being recognized as a gemologist usually involves having credentials from one of the Institutes for Gem(m)ological Studies discussed below (see '''Becoming a Gemologist''' below).<br />
<br />
===What are gemstones?===<br />
<br />
Gemstones are usually [[mineral]]s but sometimes [[organic | <SPAN title=" derived from a living organism " class="popup">organic</SPAN>]] substances.<br />
What separates them from minerals in general is that they are used in jewelry or for ornamentation. That is a very thin line of separation, but usually we take 4 factors into account:<br />
<br />
* [[Durability]]<br />
* [[Rarity]]<br />
* [[Beauty]]<br />
* [[Acceptability]]<br />
<br />
And, of course, there is a 5th factor:<br />
<br />
* [[Fashion]] <br />
<br />
All the factors above are very subjective. For instance, [[amber]] has very poor durability, isn't very rare and in general is not highly priced. Yet it is considered to be a gem due to its beauty.<br />
<br />
On the other hand, most [[sapphire]] has good durability but can be very unattractive and cheap. Only a small portion of all sapphires mined have good color/beauty. The same can be said for [[diamond]]; the vast majority of diamonds mined are used for industrial purposes because they lack the necessary beauty to be worn as jewelery.<br />
<br />
==Becoming a Gemologist==<br />
<br />
Becoming a gemologist in general means hard work and commitment. A wise teacher once said "You are only permitted to read books related to our trade and a religious book of your choice from now on . . . for the rest of your life".<br />
<br />
===Education===<br />
<br />
Although you can find very useful information on the Internet (like here), we '''strongly''' suggest that you take formal training from one of the established institutes listed below. Our editors have graduated from at least one of them.<br />
<br />
====Gem-A====<br />
<br />
Better known as The Gemmological Association and Gem Testing Laboratory of Great Britain, this school is London based with departments worldwide. It offers distance tutoring as well as teaching centers.<br><br />
The primary focus is on in-depth theory and the exams are the hardest to take in the industry. A fellowship of Gem-A means esteem. <br />
<br />
Costs:<br />
<br />
Foundation correspondence course GBP 993.00<br><br />
Diploma correspondence course GBP 1356.00 (on completion is granted the FGA title).<br />
<br />
Gem Diamond diploma course GBP 1584.00 (on completion is granted the DGA title).<br />
<br />
Website http://gem-a.info/<br />
<br />
====GIA====<br />
<br />
The Gemological Institute of America is the most prestigious and respected institute for gemology within the United States. Its main location is in Carlsbad, California, with facilities in New York and Los Angeles. Correspondence courses are available and encouraged. <br />
It was established in 1931, and currently the GIA is the world’s largest and one of the most respected nonprofit institutes of gemological research and learning internationally.<br />
It employs nearly 900, including scientists, diamond graders, and educators.<br />
<br />
Costs:<br />
<br />
On campus (CB/NY/LA): 6 month continuous program (780 hours) $13,995<br />
<br />
Distance Education: GEM130, GEM230, GEM230L, GEM120, GEM220,GEM220L, GEM240, GEM240L (Maximum completion time: 63 months) $6,975 ($7,395 International)<br />
<br />
What you earn: Graduate Gemologist Diploma, Graduate Diamonds Diploma, Graduate Colored Stones Diploma<br><br />
Website: http://www.gia.edu<br />
<br />
====AIGS====<br />
Thailand is in the heart of Southeast Asia's gem and jewelry production and trading area. It presents you with an extraordinary opportunity to learn gemology in theory and practice while experiencing the gem business in a three dimensional way. <br />
<br />
The A.G. program, which leads to the A.G. (Accredited Gemologist) Diploma, includes the four core courses:<br> <br />
:E102: Gem Identification<br><br />
:E103: Diamond Grading and Pricing<br><br />
:E201: Colored Stone Grading and Pricing<br><br />
:E301: Synthetic and Treated Gem Identification. <br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthetics and Treated Gems”. <br />
<br />
Students enrolling in the entire A.G. program are entitled to a 15% discount off the total tuition fee. Courses must be taken within one year of the first date of payment. Beyond the one year period, students will be subjected to any tuition increases that may have occurred. (Example: Old fee = 20,000 Baht, New fee in effect since date of enrollment = 22,000 Baht, Additional amount to be paid = 2,000 Baht.)<br />
<br />
Living expenses and general overhead are amazingly low compared to countries such as USA, Japan and most of Europe. Students studying at the AIGS can live with a US$600 to US$1000 budget per month including lodging near the school, weekend field trips, restaurants and entertainment. Of course, you can spend much more if you want to, but this amount yields a comfortable lifestyle!<br><br />
Website: http://www.aigsthailand.com/<br />
<br />
====DGemG====<br />
The Deutsche Gemmologische Gesellschaft (The Educational Training Center of the German Gemmological Association) is located in Idar-Oberstein, Germany. Idar-Oberstein is an international colored stone gem capital, where gem cutting has been traditionally mastered for centuries. It is currently bustling with local gem artists and studios. It has, perhaps, the highest per capita population of gem cutters in the world! The German Gemmological Association was founded in 1932.<br />
Its laboratories have modern state of the art equipment, and one of the most extensive colored and exotic gemstone collections available.<br />
<br />
Costs:<br />
<br />
Euro 5,800.00 <br><br />
<br />
Website:http://www.dgemg.de/gemmologen_eng/index.php?seite=home<br />
<br />
====FGAA====<br />
<br />
The Gemmological Association of Australia (GAA), founded in 1945, is Australia’s historic trade-accepted non-profit educational authority for gemology. <br><br />
They offer gemological courses in 6 state divisions.<br />
<br />
Costs: contact one of the six state divisions for pricing.<br />
<br />
Website: [http://www.gem.org.au www.gem.org.au]<br />
<br />
====CGA====<br />
<br />
The Canadian Gemmological Association, based in Toronto Canada, is a Canada-wide professional organization which has set the standard for excellence in the practice of gemology. It was founded in 1958 by Dean S.M. Field, and has since provided training in gemology to persons dealing with gemstones in the jewelery industry and to hobbyists for better appreciation and possible new career opportunities within gemology.<br />
<br />
They offer a one-year correspondence course as well classes on location.<br />
<br />
Costs:<br />
<br />
The two-year correspondence course, leading to a Diploma in Gemmology and a Fellowship (FCGmA) in the Canadian Gemmological Association, is offered for CAD 2,020.00<br />
<br />
Website [http://www.canadiangemmological.com/ canadagemmological.com]<br />
<br />
===Post Graduate===<br />
<br />
After gaining your gemological diploma, the real fun starts. You will know the basics and more importantly you will know how to read the many articles published in various [[periodicals]].<br><br />
If you keep up to date and involved, you will be a good gemologist one day.<br />
<br />
====Career Opportunities====<br />
<br />
As with any profession, it is all up to you what you will become and what your salary will be.<br />
<br />
Think of a gemological diploma as if you have finished your first year in college and the pay rate according to that when you start out. You will be qualified to find jobs in gemological laboratories worldwide and will be the key figure in the local jewelry store. You may become manager of a telsell company, start your own gem trading business, become an appraiser, or you might just stay shoveling municipal gardens etc. Anything you set your mind to. Pay rate is according to experience and market.<br /><br />
Best advice is to start networking from the start and to seek a new employer every few years so you can gain as much know-how as you can.</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Introduction_to_Gemology&diff=5710Introduction to Gemology2007-02-15T01:38:40Z<p>Tom Goodwin, G.G.: Added ? mark to "What are gemstones"</p>
<hr />
<div>==General information on Gemology==<br />
<br />
===What is Gemology===<br />
<br />
'''Gemology''' is the scientific study of gemstones, which often involves the study of mineralogical fundamentals such as formations, genesis, localities, physical properties and identification of gemstones. It includes the basic knowledge of structural, crystallographic, chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned.<br />
<br />
''Special Gemology'' deals with categories and varieties of gemstones, synthetic stones and imitations. Conventionally, the organic substances such as amber, pearls, coral and the non-minerals are also included in this subject of special gemology.<br />
<br />
''Practical Gemology'' refers to the application of the knowledge of characteristics and properties of gemstones in identification or separation of synthetics and imitations. Diamond grading is included in practical gemology.<br />
<br />
===What is a Gemologist===<br />
<br />
A gemologist is someone who studies gemstones. Being recognized as a gemologist usually involves having credentials from one of the Institutes for Gem(m)ological Studies discussed below (see '''Becoming a Gemologist''' below).<br />
<br />
===What are gemstones?===<br />
<br />
Gemstones are usually [[mineral]]s but sometimes [[organic | <SPAN title=" derived from a living organism " class="popup">organic</SPAN>]] substances.<br />
What separates them from minerals in general is that they are used in jewelry or for ornamentation. That is a very thin line of separation, but usually we take 4 factors into account:<br />
<br />
* [[Durability]]<br />
* [[Rarity]]<br />
* [[Beauty]]<br />
* [[Acceptability]]<br />
<br />
And, of course, there is a 5th factor:<br />
<br />
* [[Fashion]] <br />
<br />
All the factors above are very subjective. For instance, [[amber]] has very poor durability, isn't very rare and in general is not highly priced. Yet it is considered to be a gem due to its beauty.<br />
<br />
On the other hand, most [[sapphire]] has good durability but can be very unattractive and cheap. Only a small portion of all sapphires mined have good color/beauty. The same can be said for [[diamond]]; the vast majority of diamonds mined are used for industrial purposes because they lack the necessary beauty to be worn as jewelery.<br />
<br />
==Becoming a Gemologist==<br />
<br />
Becoming a gemologist in general means hard work and commitment. A wise teacher once said "You are only permitted to read books related to our trade and a religious book of your choice from now on . . . for the rest of your life".<br />
<br />
===Education===<br />
<br />
Although you can find very useful information on the Internet (like here), we '''strongly''' suggest that you take formal training from one of the established institutes listed below. Our editors have graduated from at least one of them.<br />
<br />
====Gem-A====<br />
<br />
Better known as The Gemmological Association and Gem Testing Laboratory of Great Britain, this school is London based with departments worldwide. It offers distance tutoring as well as teaching centers.<br><br />
The primary focus is on in-depth theory and the exams are the hardest to take in the industry. A fellowship of Gem-A means esteem. <br />
<br />
Costs:<br />
<br />
Foundation correspondence course GBP 993.00<br><br />
Diploma correspondence course GBP 1356.00 (on completion is granted the FGA title).<br />
<br />
Gem Diamond diploma course GBP 1584.00 (on completion is granted the DGA title).<br />
<br />
Website http://gem-a.info/<br />
<br />
====GIA====<br />
<br />
The Gemological Institute of America is the most prestigious and respected institute for gemology within the United States. Its main location is in Carlsbad, California, with facilities in New York and Los Angeles. Correspondence courses are available and encouraged. <br />
It was established in 1931, and currently the GIA is the world’s largest and one of the most respected nonprofit institutes of gemological research and learning internationally.<br />
It employs nearly 900, including scientists, diamond graders, and educators.<br />
<br />
Costs:<br />
<br />
On campus (CB/NY/LA): 6 month continuous program (780 hours) $13,995<br />
<br />
Distance Education: GEM130, GEM230, GEM230L, GEM120, GEM220,GEM220L, GEM240, GEM240L (Maximum completion time: 63 months) $6,975 ($7,395 International)<br />
<br />
What you earn: Graduate Gemologist Diploma, Graduate Diamonds Diploma, Graduate Colored Stones Diploma<br><br />
Website: http://www.gia.edu<br />
<br />
====AIGS====<br />
Thailand is in the heart of Southeast Asia's gem and jewelry production and trading area. It presents you with an extraordinary opportunity to learn gemology in theory and practice while experiencing the gem business in a three dimensional way. <br />
<br />
The A.G. program, which leads to the A.G. (Accredited Gemologist) Diploma, includes the four core courses:<br> <br />
:E102: Gem Identification<br><br />
:E103: Diamond Grading and Pricing<br><br />
:E201: Colored Stone Grading and Pricing<br><br />
:E301: Synthetic and Treated Gem Identification. <br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthetics and Treated Gems”. <br />
<br />
Students enrolling in the entire A.G. program are entitled to a 15% discount off the total tuition fee. Courses must be taken within one year of the first date of payment. Beyond the one year period, students will be subjected to any tuition increases that may have occurred. (Example: Old fee = 20,000 Baht, New fee in effect since date of enrollment = 22,000 Baht, Additional amount to be paid = 2,000 Baht.)<br />
<br />
Living expenses and general overhead are amazingly low compared to countries such as USA, Japan and most of Europe. Students studying at the AIGS can live with a US$600 to US$1000 budget per month including lodging near the school, weekend field trips, restaurants and entertainment. Of course, you can spend much more if you want to, but this amount yields a comfortable lifestyle!<br><br />
Website: http://www.aigsthailand.com/<br />
<br />
====DGemG====<br />
The Deutsche Gemmologische Gesellschaft (The Educational Training Center of the German Gemmological Association) is located in Idar-Oberstein, Germany. Idar-Oberstein is an international colored stone gem capital, where gem cutting has been traditionally mastered for centuries. It is currently bustling with local gem artists and studios. It has, perhaps, the highest per capita population of gem cutters in the world! The German Gemmological Association was founded in 1932.<br />
Its laboratories have modern state of the art equipment, and one of the most extensive colored and exotic gemstone collections available.<br />
<br />
Costs:<br />
<br />
Euro 5,800.00 <br><br />
<br />
Website:http://www.dgemg.de/gemmologen_eng/index.php?seite=home<br />
<br />
====FGAA====<br />
<br />
The Gemmological Association of Australia (GAA), founded in 1945, is Australia’s historic trade-accepted non-profit educational authority for gemology. <br><br />
They offer gemological courses in 6 state divisions.<br />
<br />
Costs: contact one of the six state divisions for pricing.<br />
<br />
Website: [http://www.gem.org.au www.gem.org.au]<br />
<br />
====CGA====<br />
<br />
The Canadian Gemmological Association, based in Toronto Canada, is a Canada-wide professional organization which has set the standard for excellence in the practice of gemology. It was founded in 1958 by Dean S.M. Field, and has since provided training in gemology to persons dealing with gemstones in the jewelery industry and to hobbyists for better appreciation and possible new career opportunities within gemology.<br />
<br />
They offer a one-year correspondence course as well classes on location.<br />
<br />
Costs:<br />
<br />
The two-year correspondence course, leading to a Diploma in Gemmology and a Fellowship (FCGmA) in the Canadian Gemmological Association, is offered for CAD 2,020.00<br />
<br />
Website [http://www.canadiangemmological.com/ canadagemmological.com]<br />
<br />
===Post Graduate===<br />
<br />
After gaining your gemological diploma, the real fun starts. You will know the basics and more importantly you will know how to read the many articles published in various [[periodicals]].<br><br />
If you keep up to date and involved, you will be a good gemologist one day.<br />
<br />
====Career Opportunities====<br />
<br />
As with any profession, it is all up to you what you will become and what your salary will be.<br />
<br />
Think of a gemological diploma as if you have finished your first year in college and the pay rate according to that when you start out. You will be qualified to find jobs in gemological laboratories worldwide and will be the key figure in the local jewelry store. You may become manager of a telsell company, start your own gem trading business, become an appraiser, or you might just stay shoveling municipal gardens etc. Anything you set your mind to. Pay rate is according to experience and market.<br /><br />
Best advice is to start networking from the start and to seek a new employer every few years so you can gain as much know-how as you can.</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Introduction_to_Gemology&diff=5709Talk:Introduction to Gemology2007-02-15T01:34:09Z<p>Tom Goodwin, G.G.: </p>
<hr />
<div>== quick draft ==<br />
<br />
This is just a quick draft of what it could look like, feel free to edit --[[User:Doos|Doos]] 12:44, 1 February 2006 (PST)<br />
<br />
:Shouldn't availability also be part of the "what makes a gemstone" section? Africanuck, March 8<br />
<br />
Yes that is a big part of it, but that is covered in "rarity". Although "availability" and "rarity" are usually the same factors, it may be artificial. Like the diamond cartel and probably also tanzanite. Furthermore politcs may play a role in this. For the most part this is not the case fortunatly. Feel free to define "rarity". --[[User:Doos|Doos]] 14:50, 8 March 2006 (PST)<br />
<br />
Ok, I pulled out my FGA stuff, what they list is acceptability (not availability, you are right that is rarity, silly me) but don't list price as a criteria.... You probably know more than I, but some of the stones that are considered gemstones are pretty cheap, and I'm not too clear on how price enter into it other than as a reflection of it's desirability (often dictated by fashion) and availability?<br />
<br />
One other question, is that supposed to be inorganic or organic? --[[User:Africanuck|Africanuck]] 06:51, 9 March 2006 (PST)<br />
<br />
:oops, organic ofcourse. You are right, let's drop "price". --[[User:Doos|Doos]] 07:16, 9 March 2006 (PST)<br />
<br />
changed inorganic to organic and changed price to acceptability --[[User:Africanuck|Africanuck]] 07:35, 9 March 2006 (PST)<br />
<br />
I'm also kind of wondering if "fashion" really fits in there... it's not really a criteria of whether or not a stone is a gem, and might be more appropriate to have it as part of the acceptability or rarity definitions. Or if we are going to touch on the subject of value, it might be added there. What do you think? --[[User:Africanuck|Africanuck]] 11:08, 10 March 2006 (PST)<br />
<br />
:Well fashion is a factor for much of the lower end gemstones (and at times for higher ends). If you look at the early 19th century you will find that lava stone was used widely in jewelry. Although we don't regard lava stone anything more than a curiousity in antique jewelry (studies showed that many of it was mere cement), it was used extensive in jewelry then (mainly due to the excavations of Pompeii and Herculanium). Painite is a new craze and might well be incorperated more a more into jewelry, also transforming it from a mineral into a gem. Ammolite is another example, it hardly passes the durability/rarity test. Yet many people seem to like it. So fashion plays a role. It's a thin line, a very thin one in many cases. --[[User:Doos|Doos]] 12:27, 10 March 2006 (PST)<br />
<br />
:Maybe acceptability/fashion .. I could feel comfortable with that. --[[User:Doos|Doos]] 12:32, 10 March 2006 (PST)<br />
== rollback ==<br />
<br />
Africa edited the Gem-A section and I tested the rollback .. so I needed to put her edits back by hand. Use 'rollback' with care so it seems.<br />
<br />
== AIGS section ==<br />
<br />
In the AIGS section, the following paragraphs are confusing to me. Any help on this?<br />
<br />
"The A.G. (Accredited Gemologist ) Diploma :<br />
<br />
The A.G. program includes the 4 core courses: E102: Gem Identification, E103: Diamond Grading and Pricing, E201: Colored Stone Grading and Pricing, E301: Synthetic and Treated Gem Identification.<br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthethics and Treated Gems”. "<br />
<br />
also, i think CGA should be added to educational institutes.<br />
<br />
: I can read it alright, but if it's confusing for you, then probably to others aswell.Is it the numbers that make it hard to read (eg. E102 etc)? I added the cga.--[[User:Doos|Doos]] 06:33, 28 February 2006 (PST)<br />
<br />
thanks for the CGA, doos. what confuses me about AIGS is the first line with the colon -- what does that refer to? to the following paragraphs? i see now that the last two really do link up fine (the paragraphing confused me but now i see it is ok). it is the first line that seems to be hanging in the wind, to me anyway.<br />
<br />
:I think that refers to the module codes of the courses. I didn't write that part so I dont really know. Rewrite it if you think that could be clearer.<br />
<br />
<br />
ok, did. check it out to see if i botched it.<br />
<br />
== tellsell ==<br />
<br />
under career opps, what is a "tellsell company"? [[User:Gemma|Gemma]] 20:35, 2 November 2006 (PST)<br />
: maybe that should read "telsell"? .. like JTV --[[User:Doos|Doos]] 07:13, 3 November 2006 (PST)<br />
<br />
that makes sense, thanks [[User:Gemma|Gemma]] 16:53, 3 November 2006 (PST)<br />
<br />
spell checked and edited [[User:Gemma|Gemma]] 20:19, 6 November 2006 (PST)<br />
<br />
== Definition of Gemologist ==<br />
A lot of people (like rockhounds) study gem minerals. Does that make them academically trained? When I think of anyone who is a "ologist" I think of formal academic training and achievement to attain such a title. In my opinion, because of this, the definition of "gemologist" needs to be edited and expanded here reflecting the professional full time work and dedication involved. I know a lot of amateur "gemologists" who couldn't separate glass from diamond. NO JOKE! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 17:32, 14 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Introduction_to_Gemology&diff=5708Talk:Introduction to Gemology2007-02-15T01:32:21Z<p>Tom Goodwin, G.G.: Definition of "Gemologist?"</p>
<hr />
<div>== quick draft ==<br />
<br />
This is just a quick draft of what it could look like, feel free to edit --[[User:Doos|Doos]] 12:44, 1 February 2006 (PST)<br />
<br />
:Shouldn't availability also be part of the "what makes a gemstone" section? Africanuck, March 8<br />
<br />
Yes that is a big part of it, but that is covered in "rarity". Although "availability" and "rarity" are usually the same factors, it may be artificial. Like the diamond cartel and probably also tanzanite. Furthermore politcs may play a role in this. For the most part this is not the case fortunatly. Feel free to define "rarity". --[[User:Doos|Doos]] 14:50, 8 March 2006 (PST)<br />
<br />
Ok, I pulled out my FGA stuff, what they list is acceptability (not availability, you are right that is rarity, silly me) but don't list price as a criteria.... You probably know more than I, but some of the stones that are considered gemstones are pretty cheap, and I'm not too clear on how price enter into it other than as a reflection of it's desirability (often dictated by fashion) and availability?<br />
<br />
One other question, is that supposed to be inorganic or organic? --[[User:Africanuck|Africanuck]] 06:51, 9 March 2006 (PST)<br />
<br />
:oops, organic ofcourse. You are right, let's drop "price". --[[User:Doos|Doos]] 07:16, 9 March 2006 (PST)<br />
<br />
changed inorganic to organic and changed price to acceptability --[[User:Africanuck|Africanuck]] 07:35, 9 March 2006 (PST)<br />
<br />
I'm also kind of wondering if "fashion" really fits in there... it's not really a criteria of whether or not a stone is a gem, and might be more appropriate to have it as part of the acceptability or rarity definitions. Or if we are going to touch on the subject of value, it might be added there. What do you think? --[[User:Africanuck|Africanuck]] 11:08, 10 March 2006 (PST)<br />
<br />
:Well fashion is a factor for much of the lower end gemstones (and at times for higher ends). If you look at the early 19th century you will find that lava stone was used widely in jewelry. Although we don't regard lava stone anything more than a curiousity in antique jewelry (studies showed that many of it was mere cement), it was used extensive in jewelry then (mainly due to the excavations of Pompeii and Herculanium). Painite is a new craze and might well be incorperated more a more into jewelry, also transforming it from a mineral into a gem. Ammolite is another example, it hardly passes the durability/rarity test. Yet many people seem to like it. So fashion plays a role. It's a thin line, a very thin one in many cases. --[[User:Doos|Doos]] 12:27, 10 March 2006 (PST)<br />
<br />
:Maybe acceptability/fashion .. I could feel comfortable with that. --[[User:Doos|Doos]] 12:32, 10 March 2006 (PST)<br />
== rollback ==<br />
<br />
Africa edited the Gem-A section and I tested the rollback .. so I needed to put her edits back by hand. Use 'rollback' with care so it seems.<br />
<br />
== AIGS section ==<br />
<br />
In the AIGS section, the following paragraphs are confusing to me. Any help on this?<br />
<br />
"The A.G. (Accredited Gemologist ) Diploma :<br />
<br />
The A.G. program includes the 4 core courses: E102: Gem Identification, E103: Diamond Grading and Pricing, E201: Colored Stone Grading and Pricing, E301: Synthetic and Treated Gem Identification.<br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthethics and Treated Gems”. "<br />
<br />
also, i think CGA should be added to educational institutes.<br />
<br />
: I can read it alright, but if it's confusing for you, then probably to others aswell.Is it the numbers that make it hard to read (eg. E102 etc)? I added the cga.--[[User:Doos|Doos]] 06:33, 28 February 2006 (PST)<br />
<br />
thanks for the CGA, doos. what confuses me about AIGS is the first line with the colon -- what does that refer to? to the following paragraphs? i see now that the last two really do link up fine (the paragraphing confused me but now i see it is ok). it is the first line that seems to be hanging in the wind, to me anyway.<br />
<br />
:I think that refers to the module codes of the courses. I didn't write that part so I dont really know. Rewrite it if you think that could be clearer.<br />
<br />
<br />
ok, did. check it out to see if i botched it.<br />
<br />
== tellsell ==<br />
<br />
under career opps, what is a "tellsell company"? [[User:Gemma|Gemma]] 20:35, 2 November 2006 (PST)<br />
: maybe that should read "telsell"? .. like JTV --[[User:Doos|Doos]] 07:13, 3 November 2006 (PST)<br />
<br />
that makes sense, thanks [[User:Gemma|Gemma]] 16:53, 3 November 2006 (PST)<br />
<br />
spell checked and edited [[User:Gemma|Gemma]] 20:19, 6 November 2006 (PST)<br />
<br />
== Definition of Gemologist ==<br />
A lot of people (like rockhounds) study gem minerals. Does that make them academically trained? When I think of anyone who is a "ologist" I think of formal academic training and achievement to attain such a title. In my opinion, because of this the definition of "gemologist" needs to be edited here reflecting the professional full time work and dedication involved. I know a lot of amateur "gemologists" who couldn't separate glass from diamond. NO JOKE! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 17:32, 14 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Introduction_to_Gemology&diff=5707Introduction to Gemology2007-02-15T01:26:37Z<p>Tom Goodwin, G.G.: Edited "is the science and study of gemstones" to the scientific study of gemstones.</p>
<hr />
<div>==General information on Gemology==<br />
<br />
===What is Gemology===<br />
<br />
'''Gemology''' is the scientific study of gemstones, which often involves the study of mineralogical fundamentals such as formations, genesis, localities, physical properties and identification of gemstones. It includes the basic knowledge of structural, crystallographic, chemical and physical characteristics and properties of gems. It also involves the way in which gemstones are fashioned.<br />
<br />
''Special Gemology'' deals with categories and varieties of gemstones, synthetic stones and imitations. Conventionally, the organic substances such as amber, pearls, coral and the non-minerals are also included in this subject of special gemology.<br />
<br />
''Practical Gemology'' refers to the application of the knowledge of characteristics and properties of gemstones in identification or separation of synthetics and imitations. Diamond grading is included in practical gemology.<br />
<br />
===What is a Gemologist===<br />
<br />
A gemologist is someone who studies gemstones. Being recognized as a gemologist usually involves having credentials from one of the Institutes for Gem(m)ological Studies discussed below (see '''Becoming a Gemologist''' below).<br />
<br />
===What are gemstones===<br />
<br />
Gemstones are usually [[mineral]]s but sometimes [[organic | <SPAN title=" derived from a living organism " class="popup">organic</SPAN>]] substances.<br />
What separates them from minerals in general is that they are used in jewelry or for ornamentation. That is a very thin line of separation, but usually we take 4 factors into account:<br />
<br />
* [[Durability]]<br />
* [[Rarity]]<br />
* [[Beauty]]<br />
* [[Acceptability]]<br />
<br />
And, of course, there is a 5th factor:<br />
<br />
* [[Fashion]]<br />
<br />
All the factors above are very subjective. For instance, [[amber]] has very poor durability, isn't very rare and in general is not highly priced. Yet it is considered to be a gem due to its beauty.<br />
<br />
On the other hand, most [[sapphire]] has good durability but can be very unattractive and cheap. Only a small portion of all sapphires mined have good color/beauty. The same can be said for [[diamond]]; the vast majority of diamonds mined are used for industrial purposes because they lack the necessary beauty to be worn as jewelery.<br />
<br />
==Becoming a Gemologist==<br />
<br />
Becoming a gemologist in general means hard work and commitment. A wise teacher once said "You are only permitted to read books related to our trade and a religious book of your choice from now on . . . for the rest of your life".<br />
<br />
===Education===<br />
<br />
Although you can find very useful information on the Internet (like here), we '''strongly''' suggest that you take formal training from one of the established institutes listed below. Our editors have graduated from at least one of them.<br />
<br />
====Gem-A====<br />
<br />
Better known as The Gemmological Association and Gem Testing Laboratory of Great Britain, this school is London based with departments worldwide. It offers distance tutoring as well as teaching centers.<br><br />
The primary focus is on in-depth theory and the exams are the hardest to take in the industry. A fellowship of Gem-A means esteem. <br />
<br />
Costs:<br />
<br />
Foundation correspondence course GBP 993.00<br><br />
Diploma correspondence course GBP 1356.00 (on completion is granted the FGA title).<br />
<br />
Gem Diamond diploma course GBP 1584.00 (on completion is granted the DGA title).<br />
<br />
Website http://gem-a.info/<br />
<br />
====GIA====<br />
<br />
The Gemological Institute of America is the most prestigious and respected institute for gemology within the United States. Its main location is in Carlsbad, California, with facilities in New York and Los Angeles. Correspondence courses are available and encouraged. <br />
It was established in 1931, and currently the GIA is the world’s largest and one of the most respected nonprofit institutes of gemological research and learning internationally.<br />
It employs nearly 900, including scientists, diamond graders, and educators.<br />
<br />
Costs:<br />
<br />
On campus (CB/NY/LA): 6 month continuous program (780 hours) $13,995<br />
<br />
Distance Education: GEM130, GEM230, GEM230L, GEM120, GEM220,GEM220L, GEM240, GEM240L (Maximum completion time: 63 months) $6,975 ($7,395 International)<br />
<br />
What you earn: Graduate Gemologist Diploma, Graduate Diamonds Diploma, Graduate Colored Stones Diploma<br><br />
Website: http://www.gia.edu<br />
<br />
====AIGS====<br />
Thailand is in the heart of Southeast Asia's gem and jewelry production and trading area. It presents you with an extraordinary opportunity to learn gemology in theory and practice while experiencing the gem business in a three dimensional way. <br />
<br />
The A.G. program, which leads to the A.G. (Accredited Gemologist) Diploma, includes the four core courses:<br> <br />
:E102: Gem Identification<br><br />
:E103: Diamond Grading and Pricing<br><br />
:E201: Colored Stone Grading and Pricing<br><br />
:E301: Synthetic and Treated Gem Identification. <br />
<br />
These 4 courses can be studied in any order, in one or several study periods at AIGS. It is recommended that “Gem Identification” be studied before “Synthetics and Treated Gems”. <br />
<br />
Students enrolling in the entire A.G. program are entitled to a 15% discount off the total tuition fee. Courses must be taken within one year of the first date of payment. Beyond the one year period, students will be subjected to any tuition increases that may have occurred. (Example: Old fee = 20,000 Baht, New fee in effect since date of enrollment = 22,000 Baht, Additional amount to be paid = 2,000 Baht.)<br />
<br />
Living expenses and general overhead are amazingly low compared to countries such as USA, Japan and most of Europe. Students studying at the AIGS can live with a US$600 to US$1000 budget per month including lodging near the school, weekend field trips, restaurants and entertainment. Of course, you can spend much more if you want to, but this amount yields a comfortable lifestyle!<br><br />
Website: http://www.aigsthailand.com/<br />
<br />
====DGemG====<br />
The Deutsche Gemmologische Gesellschaft (The Educational Training Center of the German Gemmological Association) is located in Idar-Oberstein, Germany. Idar-Oberstein is an international colored stone gem capital, where gem cutting has been traditionally mastered for centuries. It is currently bustling with local gem artists and studios. It has, perhaps, the highest per capita population of gem cutters in the world! The German Gemmological Association was founded in 1932.<br />
Its laboratories have modern state of the art equipment, and one of the most extensive colored and exotic gemstone collections available.<br />
<br />
Costs:<br />
<br />
Euro 5,800.00 <br><br />
<br />
Website:http://www.dgemg.de/gemmologen_eng/index.php?seite=home<br />
<br />
====FGAA====<br />
<br />
The Gemmological Association of Australia (GAA), founded in 1945, is Australia’s historic trade-accepted non-profit educational authority for gemology. <br><br />
They offer gemological courses in 6 state divisions.<br />
<br />
Costs: contact one of the six state divisions for pricing.<br />
<br />
Website: [http://www.gem.org.au www.gem.org.au]<br />
<br />
====CGA====<br />
<br />
The Canadian Gemmological Association, based in Toronto Canada, is a Canada-wide professional organization which has set the standard for excellence in the practice of gemology. It was founded in 1958 by Dean S.M. Field, and has since provided training in gemology to persons dealing with gemstones in the jewelery industry and to hobbyists for better appreciation and possible new career opportunities within gemology.<br />
<br />
They offer a one-year correspondence course as well classes on location.<br />
<br />
Costs:<br />
<br />
The two-year correspondence course, leading to a Diploma in Gemmology and a Fellowship (FCGmA) in the Canadian Gemmological Association, is offered for CAD 2,020.00<br />
<br />
Website [http://www.canadiangemmological.com/ canadagemmological.com]<br />
<br />
===Post Graduate===<br />
<br />
After gaining your gemological diploma, the real fun starts. You will know the basics and more importantly you will know how to read the many articles published in various [[periodicals]].<br><br />
If you keep up to date and involved, you will be a good gemologist one day.<br />
<br />
====Career Opportunities====<br />
<br />
As with any profession, it is all up to you what you will become and what your salary will be.<br />
<br />
Think of a gemological diploma as if you have finished your first year in college and the pay rate according to that when you start out. You will be qualified to find jobs in gemological laboratories worldwide and will be the key figure in the local jewelry store. You may become manager of a telsell company, start your own gem trading business, become an appraiser, or you might just stay shoveling municipal gardens etc. Anything you set your mind to. Pay rate is according to experience and market.<br /><br />
Best advice is to start networking from the start and to seek a new employer every few years so you can gain as much know-how as you can.</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5706Diamond2007-02-15T01:21:22Z<p>Tom Goodwin, G.G.: </p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 carats]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong covalent bonding between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477, thus establishing the tradition.<br />
<br />
==Color==<br />
<br />
Diamonds are found in all colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest colors are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices. Diamonds and many other hard gemstones easily scratch glass, so this is also a useless test of identification. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT-High Pressure High Temperature Treatment===<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of internationally recognized metric weight, and does not refer to size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, each called a point. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Sillimanite&diff=5705Talk:Sillimanite2007-02-15T00:13:48Z<p>Tom Goodwin, G.G.: Established "Editing Talk:Sillimanite"</p>
<hr />
<div>'''Sillimanite Article'''<br />
<br />
This gemstone is a polymorph with andalusite and kyanite which is an interesting characteristic that can be mentioned in the article. A good start on the page! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 16:13, 14 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5704Diamond2007-02-14T22:04:46Z<p>Tom Goodwin, G.G.: Added "internationally recognized"</p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 carats]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong co-valent bonding between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477, thus establishing the tradition.<br />
<br />
==Color==<br />
<br />
Diamonds are found in all colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest colors are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices. Diamonds and many other hard gemstones easily scratch glass, so this is also a useless test of identification. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT-High Pressure High Temperature Treatment===<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of internationally recognized metric weight, and does not refer to size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, each called a point. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5703Diamond2007-02-14T21:35:18Z<p>Tom Goodwin, G.G.: Minor editing of Carat Weight.</p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 carats]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong co-valent bonding between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477, thus establishing the tradition.<br />
<br />
==Color==<br />
<br />
Diamonds are found in all colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest colors are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices. Diamonds and many other hard gemstones easily scratch glass, so this is also a useless test of identification. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT-High Pressure High Temperature Treatment===<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of metric weight, and does not refer to size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, each called a point. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5702Diamond2007-02-14T21:33:03Z<p>Tom Goodwin, G.G.: Added "metric" to weight.</p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 carats]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong co-valent bonding between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477, thus establishing the tradition.<br />
<br />
==Color==<br />
<br />
Diamonds are found in all colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest colors are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices. Diamonds and many other hard gemstones easily scratch glass, so this is also a useless test of identification. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT-High Pressure High Temperature Treatment===<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of metric weight, not size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, called points. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5701Diamond2007-02-14T21:28:02Z<p>Tom Goodwin, G.G.: Added co-valent carbon bonding as reason for hardness of diamond.</p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 carats]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong co-valent bonding between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477, thus establishing the tradition.<br />
<br />
==Color==<br />
<br />
Diamonds are found in all colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest colors are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices. Diamonds and many other hard gemstones easily scratch glass, so this is also a useless test of identification. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT-High Pressure High Temperature Treatment===<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of weight, not size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, called points. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Kyanite&diff=5700Talk:Kyanite2007-02-14T21:17:11Z<p>Tom Goodwin, G.G.: Comment on cross reference</p>
<hr />
<div>==Variable Hardness==<br />
This gem is difficult to facet because of the variable hardness. 7 across the width of the crystal and 5 along the length,(Webster). We can write about this in the text of the article. Therefore, at present; I am omitting the hardness in the template box until we can have some further discussion about what to do. The cleavage is perfect, and in two directions, easily developed too. More difficulty in cutting is due to fracture planes caused by multiple twinning. The fractures are seen as inclusions in all faceted kyanites according to the Larousse Encyclopedia which I frequently cite here. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:39, 6 February 2007 (PST)<br />
* Barbra has a section on her 4.37 carat emerald-cut kyanite over on the forum and it is fracture free. In light of this, it appears that we have found an error in the Larousse Encyclopedia regarding their statement of fractures seen as inclusions in ALL faceted kyanites. Because of this, I am going to have to fact-check ALL of the Larousse information that I use here.[[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:34, 9 February 2007 (PST)<br />
::Almost all cut gems are fracture free. That doesn't mean they don't fracture when you apply force on them. Maybe there is some confusion between fracture and parting. --[[User:Doos|Doos]] 09:27, 10 February 2007 (PST)<br />
:::There IS confusion. For instance, "false" parting in corundum. In my view, "parting" is confused also with "cleavage." [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]]<br />
::::Indeed a very usual confusion. Maybe Larousse meant that all rough kyanite is fractured, not the cut. --[[User:Doos|Doos]] 13:51, 10 February 2007 (PST)<br />
:::::Barbra has carefully examined her kyanite and it is like she said, fracture-free. She posted some microphotographs of it on the forum and is trying to identify other inclusions. If kyanite is SUPPOSED to be always fractured after faceting, she has possession of the rare exception to the rule, as per Larousse. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 23:45, 13 February 2007 (PST)<br />
==Polymorphic==<br />
Kyanite is a polymorph with andalusite and fibrolite. Perhaps this will be useful when the introduction is written. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 16:01, 6 February 2007 (PST)<br />
:Yes of course it should be included (although maybe sillimanite is a more gemmo name for fibrolite). --[[User:Doos|Doos]] 13:53, 10 February 2007 (PST)<br />
:: Agreed. sillimanite is a better name, gemologically. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 23:49, 13 February 2007 (PST)<br />
:::For the project it might be best to cross reference to each other as both might be an option in a search. --[[User:Doos|Doos]] 10:08, 14 February 2007 (PST)<br />
* Very good. A cross reference will work well. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 13:17, 14 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Kyanite&diff=5693Talk:Kyanite2007-02-14T07:49:02Z<p>Tom Goodwin, G.G.: Comment on sillimanite vs. "fibrolite"</p>
<hr />
<div>==Variable Hardness==<br />
This gem is difficult to facet because of the variable hardness. 7 across the width of the crystal and 5 along the length,(Webster). We can write about this in the text of the article. Therefore, at present; I am omitting the hardness in the template box until we can have some further discussion about what to do. The cleavage is perfect, and in two directions, easily developed too. More difficulty in cutting is due to fracture planes caused by multiple twinning. The fractures are seen as inclusions in all faceted kyanites according to the Larousse Encyclopedia which I frequently cite here. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:39, 6 February 2007 (PST)<br />
* Barbra has a section on her 4.37 carat emerald-cut kyanite over on the forum and it is fracture free. In light of this, it appears that we have found an error in the Larousse Encyclopedia regarding their statement of fractures seen as inclusions in ALL faceted kyanites. Because of this, I am going to have to fact-check ALL of the Larousse information that I use here.[[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:34, 9 February 2007 (PST)<br />
::Almost all cut gems are fracture free. That doesn't mean they don't fracture when you apply force on them. Maybe there is some confusion between fracture and parting. --[[User:Doos|Doos]] 09:27, 10 February 2007 (PST)<br />
:::There IS confusion. For instance, "false" parting in corundum. In my view, "parting" is confused also with "cleavage." [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]]<br />
::::Indeed a very usual confusion. Maybe Larousse meant that all rough kyanite is fractured, not the cut. --[[User:Doos|Doos]] 13:51, 10 February 2007 (PST)<br />
:::::Barbra has carefully examined her kyanite and it is like she said, fracture-free. She posted some microphotographs of it on the forum and is trying to identify other inclusions. If kyanite is SUPPOSED to be always fractured after faceting, she has possession of the rare exception to the rule, as per Larousse. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 23:45, 13 February 2007 (PST)<br />
==Polymorphic==<br />
Kyanite is a polymorph with andalusite and fibrolite. Perhaps this will be useful when the introduction is written. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 16:01, 6 February 2007 (PST)<br />
:Yes of course it should be included (although maybe sillimanite is a more gemmo name for fibrolite). --[[User:Doos|Doos]] 13:53, 10 February 2007 (PST)<br />
:: Agreed. sillimanite is a better name, gemologically. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 23:49, 13 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Kyanite&diff=5692Talk:Kyanite2007-02-14T07:45:30Z<p>Tom Goodwin, G.G.: Comment on kyanite fracturing.</p>
<hr />
<div>==Variable Hardness==<br />
This gem is difficult to facet because of the variable hardness. 7 across the width of the crystal and 5 along the length,(Webster). We can write about this in the text of the article. Therefore, at present; I am omitting the hardness in the template box until we can have some further discussion about what to do. The cleavage is perfect, and in two directions, easily developed too. More difficulty in cutting is due to fracture planes caused by multiple twinning. The fractures are seen as inclusions in all faceted kyanites according to the Larousse Encyclopedia which I frequently cite here. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:39, 6 February 2007 (PST)<br />
* Barbra has a section on her 4.37 carat emerald-cut kyanite over on the forum and it is fracture free. In light of this, it appears that we have found an error in the Larousse Encyclopedia regarding their statement of fractures seen as inclusions in ALL faceted kyanites. Because of this, I am going to have to fact-check ALL of the Larousse information that I use here.[[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:34, 9 February 2007 (PST)<br />
::Almost all cut gems are fracture free. That doesn't mean they don't fracture when you apply force on them. Maybe there is some confusion between fracture and parting. --[[User:Doos|Doos]] 09:27, 10 February 2007 (PST)<br />
:::There IS confusion. For instance, "false" parting in corundum. In my view, "parting" is confused also with "cleavage." [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]]<br />
::::Indeed a very usual confusion. Maybe Larousse meant that all rough kyanite is fractured, not the cut. --[[User:Doos|Doos]] 13:51, 10 February 2007 (PST)<br />
:::::Barbra has carefully examined her kyanite and it is like she said, fracture-free. She posted some microphotographs of it on the forum and is trying to identify other inclusions. If kyanite is SUPPOSED to be always fractured after faceting, she has possession of the rare exception to the rule, as per Larousse. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 23:45, 13 February 2007 (PST)<br />
==Polymorphic==<br />
Kyanite is a polymorph with andalusite and fibrolite. Perhaps this will be useful when the introduction is written. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 16:01, 6 February 2007 (PST)<br />
:Yes of course it should be included (although maybe sillimanite is a more gemmo name for fibrolite). --[[User:Doos|Doos]] 13:53, 10 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=User:Tom_Goodwin,_G.G.&diff=5666User:Tom Goodwin, G.G.2007-02-10T21:24:32Z<p>Tom Goodwin, G.G.: </p>
<hr />
<div>'''Thomas E. Goodwin, B.A., A.Sc.G., G.G.,'''<br />
Senior Staff Gemologist,<br />
Las Vegas Jewelers, <br />
3953 Las Vegas Boulevard South,<br />
Las Vegas, NV, 89119 http://www.graduategemologist.blogspot.com <br />
<br />
==Education==<br />
<br />
''Foothill High School, Santa Ana, Califonia, 1967<br />
<br />
''A.A., Santa Ana College, Liberal Arts, 1969<br />
<br />
''B.A., California State University, Fullerton, Psychology, 1974<br />
<br />
''A.Sc.G., (Associate in Science in Gemology) Santa Ana College, 1981<br />
<br />
''Certificate in Gemology, Santa Ana College, 1981<br />
<br />
''Graduate Gemologist Diploma, Gemological Institute of America, Santa Monica, California, 1985</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=User:Tom_Goodwin,_G.G.&diff=5665User:Tom Goodwin, G.G.2007-02-10T21:23:53Z<p>Tom Goodwin, G.G.: </p>
<hr />
<div>'''Thomas E. Goodwin, B.A., A.Sc.G., G.G.,'''<br />
Senior Staff Gemologist,<br />
Las Vegas Jewelers, {{user piano}}<br />
3953 Las Vegas Boulevard South,<br />
Las Vegas, NV, 89119 http://www.graduategemologist.blogspot.com <br />
<br />
==Education==<br />
<br />
''Foothill High School, Santa Ana, Califonia, 1967<br />
<br />
''A.A., Santa Ana College, Liberal Arts, 1969<br />
<br />
''B.A., California State University, Fullerton, Psychology, 1974<br />
<br />
''A.Sc.G., (Associate in Science in Gemology) Santa Ana College, 1981<br />
<br />
''Certificate in Gemology, Santa Ana College, 1981<br />
<br />
''Graduate Gemologist Diploma, Gemological Institute of America, Santa Monica, California, 1985</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Kyanite&diff=5664Talk:Kyanite2007-02-10T21:20:45Z<p>Tom Goodwin, G.G.: Added comment regarding fracture and parting.</p>
<hr />
<div>==Variable Hardness==<br />
This gem is difficult to facet because of the variable hardness. 7 across the width of the crystal and 5 along the length,(Webster). We can write about this in the text of the article. Therefore, at present; I am omitting the hardness in the template box until we can have some further discussion about what to do. The cleavage is perfect, and in two directions, easily developed too. More difficulty in cutting is due to fracture planes caused by multiple twinning. The fractures are seen as inclusions in all faceted kyanites according to the Larousse Encyclopedia which I frequently cite here. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:39, 6 February 2007 (PST)<br />
* Barbra has a section on her 4.37 carat emerald-cut kyanite over on the forum and it is fracture free. In light of this, it appears that we have found an error in the Larousse Encyclopedia regarding their statement of fractures seen as inclusions in ALL faceted kyanites. Because of this, I am going to have to fact-check ALL of the Larousse information that I use here.[[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:34, 9 February 2007 (PST)<br />
::Almost all cut gems are fracture free. That doesn't mean they don't fracture when you apply force on them. Maybe there is some confusion between fracture and parting. --[[User:Doos|Doos]] 09:27, 10 February 2007 (PST)<br />
:::There IS confusion. For instance, "false" parting in corundum. In my view, "parting" is confused also with "cleavage." [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]]<br />
==Polymorphic==<br />
Kyanite is a polymorph with andalusite and fibrolite. Perhaps this will be useful when the introduction is written. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 16:01, 6 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5658Diamond2007-02-10T03:53:53Z<p>Tom Goodwin, G.G.: </p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 carats]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong chemical bonds between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477, thus establishing the tradition.<br />
<br />
==Color==<br />
<br />
Diamonds are found in all colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest colors are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices. Diamonds and many other hard gemstones easily scratch glass, so this is also a useless test of identification. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT-High Pressure High Temperature Treatment===<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of weight, not size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, called points. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5657Diamond2007-02-10T03:51:58Z<p>Tom Goodwin, G.G.: Added text on scratching glass with diamonds/other gemstones.</p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 carats]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong chemical bonds between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477, thus establishing the tradition.<br />
<br />
==Color==<br />
<br />
Diamonds are found in all colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest colors are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices.Diamonds and many other hard gemstones easily scratch glass, so this is a useless test of identification. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT-High Pressure High Temperature Treatment===<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of weight, not size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, called points. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5656Diamond2007-02-10T03:46:16Z<p>Tom Goodwin, G.G.: Added "Colors" to modify rarest</p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 carats]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong chemical bonds between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477, thus establishing the tradition.<br />
<br />
==Color==<br />
<br />
Diamonds are found in all colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest colors are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT-High Pressure High Temperature Treatment===<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of weight, not size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, called points. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5655Diamond2007-02-10T03:44:46Z<p>Tom Goodwin, G.G.: Edited "Diamonds are found in all colors"</p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 carats]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong chemical bonds between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477, thus establishing the tradition.<br />
<br />
==Color==<br />
<br />
Diamonds are found in all colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT-High Pressure High Temperature Treatment===<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of weight, not size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, called points. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5654Diamond2007-02-10T03:42:54Z<p>Tom Goodwin, G.G.: Added "thus establishing the tradition"</p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 carats]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong chemical bonds between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477, thus establishing the tradition.<br />
<br />
==Color==<br />
<br />
All colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT-High Pressure High Temperature Treatment===<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of weight, not size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, called points. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Diamond&diff=5653Talk:Diamond2007-02-10T03:40:04Z<p>Tom Goodwin, G.G.: </p>
<hr />
<div>this is a nice write-up you two. will be fun when all the stones get a full treatment. [[User:Gemma|Gemma]] 05:55, 23 December 2006 (PST)<br />
<br />
*I expanded the list of diamond simulants. There is a lot to be written on simulation alone! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 12:14, 14 January 2007 (PST)<br />
<br />
*Then go bananas Tom... all help is more than welcome. --[[User:Africanuck|Africanuck]] 12:46, 14 January 2007 (PST)<br />
<br />
* I also expanded the section on Durability. Maybe I am "jumping" the gun here by mentioning girdles, pavillions, and culets where they haven't been previously defined in the article under the category of "fashioning or polishing," but I figure that we can link everything together in a logical manner as information is added. Just working on this one section shows me the tremendous amount of effort and time the founders of this project have put into it. Incidentally, I think this project deserves some good press. I am going to contact my good friend and colleague, Gary Roskin (Senior Editor of JCK Magazine) and see if he would like to do a feature article on it. He knows Ms. Voltaire as he spoke at one of her GIA alumni chapter meetings in San Francisco. You guys deserve deserve an interview! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 16:13, 14 January 2007 (PST)<br />
<br />
* Let's see. The American gemologists describe everything in terms of hue, tone ("shades" to our F.G.A. colleagues?) and saturation. I can see that we are going to have nomenclature difficulties, but that is perfectly all right as long as the readers know what we are trying to describe! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:08, 18 January 2007 (PST)<br />
<br />
::My motivation was not very clear I must admit. But "hue" relates to a specific opaque "color" (blue, green, yellow etc.) while "shade" takes tone and saturation in consideration (aswell as transparency). Therefore hue is not appropiate in my view. But it is a marginal dispute. --[[User:Doos|Doos]] 14:41, 18 January 2007 (PST)<br />
: This illustrates to me how difficult it is to discuss "color" even amongst trained experts. In my opinion, definitions need to be extremely precise and undisputed otherwise confusion ensues. Pity the poor layperson! Thank You for your attention to this matter. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 15:00, 18 January 2007 (PST)<br />
<br />
*It seems to me that we need a visual scale for clarity like the scale for grading diamond color that precedes the clarity grading section. Also, are we going to go from IF--->I3 or FL---->I3? [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 13:18, 19 January 2007 (PST)<br />
<br />
::Yes a nice clarity scale should be created. On the IF/FL - I3; as we strive to be independent, all views should be presented. There is even room for the SI3 in my opinion. We are not making policy, we are reporting (but controversial ideas should be presented as such). --[[User:Doos|Doos]] 13:34, 19 January 2007 (PST)<br />
:::I concur that the EGL clarity grade of SI3 should be noted even though it is controversial. I think everyone can agree on well described explanations. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 15:08, 19 January 2007 (PST)<br />
<br />
==Diamond Cutting or Fashioning==<br />
<br />
:I propose that a separate article be established to address the rough cutting process which I think should include how rough diamonds are sorted and classified by the DTC prior to the sights in London. This article seems to address polished diamonds and their characteristics for the most part. Let's hear it for the rough! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 19:29, 9 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Talk:Diamond&diff=5652Talk:Diamond2007-02-10T03:29:24Z<p>Tom Goodwin, G.G.: Proposal of Separate Article on Diamond Cutting and and Polishing</p>
<hr />
<div>this is a nice write-up you two. will be fun when all the stones get a full treatment. [[User:Gemma|Gemma]] 05:55, 23 December 2006 (PST)<br />
<br />
*I expanded the list of diamond simulants. There is a lot to be written on simulation alone! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 12:14, 14 January 2007 (PST)<br />
<br />
*Then go bananas Tom... all help is more than welcome. --[[User:Africanuck|Africanuck]] 12:46, 14 January 2007 (PST)<br />
<br />
* I also expanded the section on Durability. Maybe I am "jumping" the gun here by mentioning girdles, pavillions, and culets where they haven't been previously defined in the article under the category of "fashioning or polishing," but I figure that we can link everything together in a logical manner as information is added. Just working on this one section shows me the tremendous amount of effort and time the founders of this project have put into it. Incidentally, I think this project deserves some good press. I am going to contact my good friend and colleague, Gary Roskin (Senior Editor of JCK Magazine) and see if he would like to do a feature article on it. He knows Ms. Voltaire as he spoke at one of her GIA alumni chapter meetings in San Francisco. You guys deserve deserve an interview! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 16:13, 14 January 2007 (PST)<br />
<br />
* Let's see. The American gemologists describe everything in terms of hue, tone ("shades" to our F.G.A. colleagues?) and saturation. I can see that we are going to have nomenclature difficulties, but that is perfectly all right as long as the readers know what we are trying to describe! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 14:08, 18 January 2007 (PST)<br />
<br />
::My motivation was not very clear I must admit. But "hue" relates to a specific opaque "color" (blue, green, yellow etc.) while "shade" takes tone and saturation in consideration (aswell as transparency). Therefore hue is not appropiate in my view. But it is a marginal dispute. --[[User:Doos|Doos]] 14:41, 18 January 2007 (PST)<br />
: This illustrates to me how difficult it is to discuss "color" even amongst trained experts. In my opinion, definitions need to be extremely precise and undisputed otherwise confusion ensues. Pity the poor layperson! Thank You for your attention to this matter. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 15:00, 18 January 2007 (PST)<br />
<br />
*It seems to me that we need a visual scale for clarity like the scale for grading diamond color that precedes the clarity grading section. Also, are we going to go from IF--->I3 or FL---->I3? [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 13:18, 19 January 2007 (PST)<br />
<br />
::Yes a nice clarity scale should be created. On the IF/FL - I3; as we strive to be independent, all views should be presented. There is even room for the SI3 in my opinion. We are not making policy, we are reporting (but controversial ideas should be presented as such). --[[User:Doos|Doos]] 13:34, 19 January 2007 (PST)<br />
:::I concur that the EGL clarity grade of SI3 should be noted even though it is controversial. I think everyone can agree on well described explanations. [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 15:08, 19 January 2007 (PST)<br />
<br />
==Diamond Cutting or Fashioning==<br />
<br />
:I propose that a separate article be established to address the rough cutting process which I think should include how rough diamonds are sorted by the DTC prior to the sights. This article seems to address polished diamonds and their characteristics for the most part. Let's hear it for the rough! [[User:Tom Goodwin, G.G.|Tom Goodwin, G.G.]] 19:29, 9 February 2007 (PST)</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5651Diamond2007-02-10T03:17:13Z<p>Tom Goodwin, G.G.: Title cleanup (type) on HPHT section</p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 carats]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong chemical bonds between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477.<br />
<br />
==Color==<br />
<br />
All colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT-High Pressure High Temperature Treatment===<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of weight, not size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, called points. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5650Diamond2007-02-10T03:05:20Z<p>Tom Goodwin, G.G.: Edited "Cts." to carats</p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 carats]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong chemical bonds between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477.<br />
<br />
==Color==<br />
<br />
All colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT - High Pressure High Temperature Treatment====<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of weight, not size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, called points. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Diamond&diff=5649Diamond2007-02-10T03:00:50Z<p>Tom Goodwin, G.G.: Added weight of Hope Diamond to photograph. Source:Larousse, page 102</p>
<hr />
<div> {{diamond}}<br />
<br />
[[Image:Hope_Diamond.jpg|left|framed|The Hope Diamond weighs 45.52 cts.]]<br clear="left" /><br />
<br />
Diamond is a polymorph (many forms) of the element carbon. Graphite is another polymorph. <br />
These two minerals share the same chemistry -- pure carbon -- but have very different structures and properties. Diamond is <br />
hard, graphite is soft (the &quot;lead&quot; of a pencil). <br />
Diamond is an excellent electrical insulator, graphite <br />
is a good conductor of electricity. Diamond is the ultimate abrasive, graphite is a very good lubricant. Diamond <br />
is transparent, graphite is opaque. Diamond crystallizes <br />
in the isometric system and graphite crystallizes in <br />
the hexagonal system. Somewhat of a surprise is that, <br />
at surface temperatures and pressures, graphite is the <br />
stable form of carbon. In fact, all diamonds at or near <br />
the surface of Earth are currently undergoing a <br />
transformation into graphite. This reaction, fortunately, <br />
is extremely slow.<br />
<br />
Diamonds have long been valued for their supreme hardness and incomparable<br />
brilliance. Chemically, a diamond is pure carbon just <br />
like the graphite used in pencils. Diamond's hardness <br />
is the result of extremely strong chemical bonds between <br />
the carbon atoms. Although most people think of diamonds <br />
as colorless, they actually occur in almost every color. <br />
Diamonds were viewed as talismanic by the ancient Hindus <br />
in India, which is where diamonds were first discovered. <br />
The most powerful stones were thought to be naturally <br />
occurring octahedrons of exceptional clarity which exhibited <br />
fire. These stones would bring the owner power, wealth, <br />
everlasting youth and good fortune. It was believed that <br />
flawed or inclusive stones could have quite the opposite <br />
effect. During the 1st century AD, prominent Romans wore <br />
uncut diamonds set in rings also as talismans. For hundreds <br />
of years, it was believed diamonds had gender. As <br />
late as 1566, Francois Ruet described two diamonds as <br />
having offspring. The first diamond engagement ring was <br />
given to Mary of Burgundy by Maximillian in 1477.<br />
<br />
==Color==<br />
<br />
All colors, but diamonds most commonly occur in shades of yellow and <br />
brown. Colorless diamonds which are graded D-E-F are much rarer. The rarest are reds, blues, pinks, and greens of intense saturation.<br />
<br />
==Spectrum==<br />
<br />
[[Image:yellow_diamond.gif|framed|left| Spectrum of yellow diamond.]]<br clear="left" /><br />
[[Image:Grown_diamond.gif|framed|left| Spectrum of brown diamond.]]<br clear="left" /><br />
<br />
==Durability==<br />
<br />
Diamonds are the hardest of all gemstones in to their ability to scratch, but they can be broken along their four planes of inherent cleavage. Historically, it has been a very foolish practice to test for identification by using a diamond phonograph<br />
needle<br />
to scratch a suspected diamond. Only a diamond can scratch a diamond and semi-destructive testing of this sort is not necessary, given modern gemological instrumentation such as thermal inertia testing devices. Fashioned or cut diamonds are vulnerable to chipping at the polished or unpolished girdle edge as well as at the bottom of the pavillion which is known as the culet. The culet is the smallest possible facet and may or not be present. Diamond cutters usually strive for maximum weight retention from the rough and sometimes omit the culet. Small culets are considered acceptable by diamond graders and serve as the 58th facet in what is known as the standard "round brilliant cut."<br />
<br />
==Localities==<br />
<br />
Diamond deposits are found world-wide, the most notable deposits being on the continents of Africa and Australia, India, and most recently Canada.<br />
<br />
==Treatments==<br />
===Laser Drilling===<br />
[[Image:drilled.jpg|framed|left| Laser Drill Hole]]<br />
This treatment involves pointing a high powered laser directly at a dark inclusion within a diamond and burning a tiny tunnel towards it. With luck, the inclusion will be altered enough by the heat of the laser to make it less noticeable. If that is not the case, a strong acid can be forced down the drill hole which will dissolve the inclusion and make it less obvious. This treatment is usually easily detected with 10x magnification. The drill hole breaks the surface of the diamond and leads in a straight line to the treated inclusion. Occasionally drill holes can be filled with glass (the same process as clarity enhancement) which makes them more difficult to detect with magnification. Laser drilling was first encountered in the 1960's. <br />
<br />
In 2000, a new type of laser drilling was developed in Israel. It is called Kiduah Meyuhad (KM). The laser focuses on an inclusion within a diamond, and causes a series of internal fractures that make the inclusion appear to "bleach out". This laser treatment looks more natural and leaves no drill holes. It resembles feather like inclusions in the diamond, which do not break the surface. Detection of diamonds that have been treated with KM can be very difficult and requires the examiner to have experience in recognising the characteristics of these microscopic fractures. Some KM treated diamonds have not been detected by major gem labs when grading.<br />
<br />
===Coating===<br />
Diamonds have been coated to disguise a low color grade, or to produce "fancy colors". The stability of the treatment varies, depending on the method used. Coated stones need special care, as aggressive ultrasonic cleaning, repairs, or re-cutting may destroy the integrity of the coating and totally change the appearance of the stone.<br><br />
For more information, read this article from [http://www.gia.edu/gemsandgemology/18578/18940/2072/back_issue_article_detail.cfm Gems & Gemology]<br />
<br />
<br />
===Clarity Enhancement===<br />
[[Image:flash.jpg|left|framed| The "flash" in a clarity enhanced diamond]]<br />
Clarity enhancing a diamond involves replacing the air in a surface reaching crack or cleavage with a substance having a similar refractive index to the diamond. This changes the relief of the inclusion making it much more difficult to see. Clarity enhancement can have a dramatic effect on improving the look of a diamond. <br><br />
Clarity enhanced diamonds are usually easily detected with magnification. The early examples of this technique produced broad flashes of color, bright red, violet and orange, in the areas of treatment. The early glass filling was not very stable and was often damaged or destroyed with ultrasonic cleaning, repairs or normal wear. <br><br />
The new generation of clarity enhancement does not produce the obvious flashes of color when viewed with magnification. Although, careful observation can reveal gas bubbles, flow patterns and partial crystallization of filler components. Still a faint color flash can be observed, but this effect is similar to the colors seen as the result of natural "strain" which produce a rainbow like pattern. So experience is necessary for positive detection. The flashes of color seen in a clarity enhanced diamond are one color at a time, whereas the colors produced by strain are spectral in appearance. <br><br />
<br />
For further information, check the websites of the companies that specialize in clarity enhancement: <br><br />
* [http://www.oved.com Oved Diamond Company]<br />
* [http://www.yehuda.com Yehuda Diamond Company]<br />
* [http://www.koss-diamonds.com Koss Diamond]<br />
<br />
===Irradiation to Produce Color Enhancement===<br />
[[Image:irradiated.jpg|left|framed| Un-natural blue/green color produced by irradiation]]<br />
The earliest experiments with diamond irradiation dates back to 1904, when diamonds were exposed to radium salts, producing a greenish coloration. These early treated diamonds proved to be radioactive, thus posing health concerns to anyone handling them. Diamonds treated with radium salt are occasionally encountered in period pieces of jewelry and should be tested with a Geiger counter as the radioactivity may still linger. <br><br />
Diamonds can also be bombarded with neutrons from a cyclotron to cause a change in color. The penetration is shallow so only stones that have already been fashioned are treated in this way. Detection of this cyclotron irradiation is quite easy as it produces a color concentration known as the "umbrella effect" The development of nuclear reactors, allowed several diamonds to be treated at a time and the depth of penetration was much greater. This allowed rough diamonds to be treated. The original color produced by treatment was green, but the diamonds could be annealed to produce pink, red, yellow, blue and orange. But these colors are not always stable when subjected to high heat, so care must be taken during repair work, using a torch. It is very difficult to detect this treatment without very sophisticated laboratory equipment. <br><br><br />
<br />
===HPHT - High Pressure High Temperature Treatment====<br />
HPHT treatments evolved from early research General Electric conducted in the 1950's in the quest for synthetic diamonds. This process is currently used to remove color from certain diamond classes (Type IIa), or to create fancy colors in Type IIa diamonds in combination with other procedures. The treatment involves subjecting the diamond to heat and pressure similar to those occuring when the diamond initially crystallized. It is claimed that this process "repairs" the crystal lattice, and changes the color. A color change of Z to D has been reported. <br><br />
HPHT is used in a combination with other treatments to produce fancy colors such as blue, orange, red, green and yellow.<br><br />
For further information read:<br />
* [http://www.gia.edu/gemsandgemology/18578/1914/524/back_issue_article_detail.cfm Gems & Gemology: Lab Notes]<br />
* [http://www.diamonds.net/news/NewsItem.aspx?ArticleID=6487 Rapaport News: GIA Confronts Challenge of HPHT]<br />
* [http://www.bellatairediamonds.com Bellataire Diamonds: Check F.A.Q.]<br />
<br />
==Synthetics==<br />
<br />
Swedish and American researchers discovered how to synthesize diamonds in the 1950's. Currently, the two methods used to synthesize diamonds are High Pressure, High Temperature (HTHP) and Chemical Vapour Deposition (CVD).<br />
<br />
==Simulants==<br />
<br />
Synthetic cubic zirconia, moissanite, yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG), strontium titanate, lithium tantalite, lithium niobate, synthetic rutile, leaded crystal (glass imitation).<br />
<br />
==Diamond Grading: The 4 C's==<br />
The 4 C's, when referring to diamond value, are color, clarity, cutting proportions and carat weight. All four components are equally important in determining the final value of a diamond. The criteria for diamond grading, most respected internationally, was developed by the Gemological Institute of America (the G.I.A.), during the 1950's. The following terminology and systems described are those of the G.I.A.<br />
<br />
===Color Grading===<br />
[[Image:Diamondcolorscale.jpg]]<br clear="left" /><br />
The color of a diamond refers to the relative amount of yellow, brown or gray body color that a stone possesses. The G.I.A. scale starts at "D" and goes through "Z", with "D" being void of any body color, and "Z" having a light yellow, brown or gray color.<br />
<br />
===Clarity Grading===<br />
<br />
===Cut: Proportion Analysis===<br />
<br />
===Carat Weight===<br />
<br />
Carat is a unit of weight, not size. There are 5 carats in a gram. The weight of a diamond is measured in carats. A carat is divided into 100 parts, called points. Each point weighs 2 milligrams.<br><br />
<br />
==External links==<br />
* [http://www.brysonburke.com/aboutdiamonds.html Diamonds]<br />
* [http://www.gemguide.com/news/archives7.htm Yellow Diamonds, by Martin Haske]<br />
* [http://www.amnh.org/exhibitions/diamonds/growing.html Growing Diamonds, American Museum of Natural History]<br />
* [http://gemologyonline.com/diamond.html Diamonds at GemologyOnline]</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Template:Rock_Crystal&diff=5648Template:Rock Crystal2007-02-10T02:52:57Z<p>Tom Goodwin, G.G.: Edited "Clear" to Colorless. "Clear" is expected to be confused with clarity rather than color.</p>
<hr />
<div>{| align=right width=250px {{table}}<br />
|-<br />
! colspan=2 | Rock Crystal (Colorless Quartz)<br />
|-<br />
| Chemical composition || SiO<sub>2</sub> Silicon dioxide<br />
|-<br />
| Crystal system || [[Crystals_&_Their_Structure#Trigonal_Crystal_System | Trigonal]]<br />
|-<br />
| Habit || Prismatic<br />
|-<br />
| Cleavage || Poor<br />
|-<br />
| Fracture || Conchoidal<br />
|-<br />
| Hardness || 7<br />
|-<br />
| Optic nature || Uniaxial +<br />
|-<br />
| Refractive index || 1.544 - 1.553<br />
|- <br />
| Birefringence || 0.009<br />
|-<br />
| Dispersion || Low, 0.013<br />
|- <br />
| Specific gravity || 2.65<br />
|-<br />
| Lustre || Vitreous<br />
|-<br />
| Pleochroism || None<br />
|}</div>Tom Goodwin, G.G.http://www.gemologyproject.com/wiki/index.php?title=Template:Topaz&diff=5647Template:Topaz2007-02-10T02:46:48Z<p>Tom Goodwin, G.G.: Added "plane" to basal</p>
<hr />
<div>{| align=right width=250px {{table}}<br />
|-<br />
! colspan=2 | Topaz<br />
|-<br />
| Chemical composition || Al<sub>2</sub>(F,OH)<sub>2</sub>SiO<sub>4</sub><br />
|-<br />
| Crystal system || Orthorhombic<br />
|-<br />
| Habit || Prismatic with pyramidal/domed terminations<br />
|-<br />
| Cleavage || Perfect, basal plane<br />
|-<br />
| Fracture || Sub-conchoidal to uneven<br />
|-<br />
| Hardness || 8<br />
|-<br />
| Optic nature || Biaxial +<br />
|-<br />
| Refractive index || 1.606-1.644<br />
|- <br />
| Birefringence || 0.008 - 0.010<br />
|-<br />
| Dispersion || Low, 0.014<br />
|- <br />
| Specific gravity || 3.49 - 3.57<br />
|-<br />
| Lustre || Vitreous<br />
|-<br />
| Pleochroism || Distinct to strong (depending on body color)<br />
|}</div>Tom Goodwin, G.G.