http://www.gemologyproject.com/wiki/api.php?action=feedcontributions&user=Russell&feedformat=atomThe Gemology Project - User contributions [en]2024-03-28T17:04:04ZUser contributionsMediaWiki 1.28.0http://www.gemologyproject.com/wiki/index.php?title=Poudretteite&diff=5509Poudretteite2007-01-22T01:08:20Z<p>Russell: </p>
<hr />
<div>{{Poudretteite}}<br />
<br />
A very rare gem, first found in Mont St. Hilaire, Quebec, Canada. Named after the Poudrette family who were the operators of the quarry where it was first discovered.<br><br><br />
<br />
Crystal System: Hexagonal<br />
<br />
Crystal Habit: As stubby, barrel shaped prismatic or bipyramidal crystals<br />
<br />
<br />
Chemical Composition: KNa2B3Si12O30 Potassium sodium boron silicate<br />
<br />
<br />
Physical Properties<br />
<br />
Hardness Approx. 5<br />
<br />
Density: 2.51(Measured) 2.53 (Calculated)<br />
<br />
Fracture: Conchoidal to splintery<br />
<br />
Tenacity: Brittle<br />
<br />
Cleavage: None reported<br />
<br />
Luminescence: None observed<br />
<br />
<br />
Optical Properties <br />
<br />
Color: Colorless to pink, purple<br />
<br />
Diaphaneity: transparent<br />
<br />
Luster: Vitreous<br />
<br />
Optical Class: Uniaxial (+)<br />
<br />
Orientation: <br />
<br />
Dispersion: <br />
<br />
Birefringence: 0.016 – 0.021<br />
<br />
Pleochroism: Colorless to pink<br />
<br />
Refractive Index: ω = 1.516 ε = 1.532 <br />
<br />
2V (measured) <br />
<br />
Visible Light Spectroscopy: <br />
<br />
Microscopy:<br />
<br />
Inclusions may include veils of two-phase (liquid + gas) inclusions and localized parallel flat tubes. <br />
<br />
Diagnostics:<br />
<br />
<br />
Phenomenon<br />
<br />
<br />
Treatments: <br />
<br />
Synthetics: <br />
<br />
Imitations: <br />
<br />
Care: <br />
<br />
<br />
Occurrence:<br />
<br />
Poudretteite was originally described in 1987 as minute crystals of no gemological interest at Mont St. Hilaire; the samples had been collected in the 1960’s. In 2000, rough was discovered in the Pain Pyit district, Mogok, Myanmar that cut a 3ct stone that was later determined to be poudretteite. As of 2004, 10 examples of poudretteite had been identified amoung Mogok stones, the largest being a 22ct crystal that was cut into a 9.4ct gem. <br />
<br />
<br />
Sources<br />
<br />
Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona<br />
<br />
Grice, J D, Ercit, T. S., Van Velthuizen, J. and Dunn P. J. (1987) The Canadian Mineralogist Vol. 25 (1987) pp 763-766 Poudretteite, KNa2B3Si12O30, a new member of the osumilite group from Mont Saint-Hilaire, Quebec, and its crystal structure<br />
<br />
Smith, Christopher P., Bosshart, G., Graeser, S., Hanni, H. and Gunther, D. (2003) Gems and Gemology Vol 39 No. 1 Poudretteite: A Rare Gem Species from the Mogok Valley<br />
<br />
<br />
External Links:<br />
<br />
<br />
<br />
==External links and aknowledgements==<br />
[http://www.aigslaboratory.com/Filearticle/54.pdf AIGS Laboratory Report on 9.41 ct faceted Poudretteite]<br><br />
[http://www.saint-hilaire.ca/en/poudret.htm Mont St. Hilaire]<br><br />
[http://rruff.geo.arizona.edu/doclib/cm/vol25/CM25_763.pdf Canadian Mineralogist Vol.25 Poudretteite]</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Pectolite&diff=5476Pectolite2007-01-20T05:46:10Z<p>Russell: /* Fluorescence */</p>
<hr />
<div>{{Pectolite}}<br />
<br />
Varietal Names: “Larimar” is a blue pectolite from the Dominican Republic; the name “Larimar” is trademarked. <br />
<br />
==Crystal Habit== <br />
Crystals are uncommon and are usually tabular. More commonly occurs as bundles of acicular needles showing either columnar or radiating fibrous structure.<br />
<br />
==Chemical composition== <br />
Sodium calcium silicate hydroxide, NaCa2Si308(OH). Minor to trace amounts of iron, potassium and copper may be present. <br />
<br />
==Diagnostics==<br />
<br />
===Color===<br />
Colorless, white, pale apple green, dark green; the Larimar variety varies from white to light medium blue (similar to turquoise) to green.<br />
<br />
===Magnification===<br />
The “Larimar” type of pectolite displays opaque red dendritic hematite, inclusions of translucent to transparent square patches of calcite to 2 mm wide, sprays of transparent to translucent grey natrolite as long prisms with square cross section, opaque blebs of native copper, and opaque blebs and euhedral crystals of chalcocite, a copper sulfide Woodruff (1989). This same assemblage of accessory minerals is present in other, non-gem quality pectolite occurrences, such as the basalts of Paterson, New Jersey. <br />
<br />
===Cleavage=== <br />
Perfect on {100} and {001}. <br />
<br />
===Specific Gravity=== <br />
2.84 to 2.90 (measured), 2.97 (calculated).<br /> <br />
Measurements of the specific gravity of Larimar ranged from 2.62 to 2.87; low range readings were probably a result of a inclusions of other minerals in the pectolite. <br />
<br />
===Refractive Index=== <br />
nα = 1.592 – 1.610, nβ = 1.603 to 1.615, nγ = 1.630 – 1.645<br />
<br />
===Fluorescence=== <br />
Woodruff and Fritsch (1989) report a turbid green fluorescence under Short Wave ultraviolet radiation and a chalky green fluorescence under Long Wave for Larimar.<br />
<br />
==Phenomenon==<br />
Larimar may exhibit localized areas that appear chatoyant resulting from oriented parallel clusters of pectolite needles.<br />
<br />
==Treatments==<br />
<br />
None known<br />
<br />
==Synthetics==<br />
<br />
None known<br />
<br />
==Imitations==<br />
<br />
None known<br />
<br />
==Occurrence== <br />
<br />
Occurs in cavities in basalts and diabases as a result of hydrothermal action.<br />
<br />
The Larimar variety of pectolite occurs in a basalt formation about 5km west of Baoruco, Dominican Republic; the pectolite was first discovered in 1974 as stream-rounded pebbles in an adjacent river.<br />
<br />
In 1884, Frank W Clarke reported that a number of Eskimo artifacts collected near Point Barrow, Alaska – originally believed to be jade - were, in fact, composed of a “interesting variety of compact pectolite, in two varieties, one pale apple green, the other dark green” [cited in Kunz (1892)]. Apparently the original source of the pectolite has not been found. Kunz also notes in 1887 geologist William P. Blake reported the discovery of a significant occurrence of compact, translucent pectolite that was “white, with a delicate shade of sea green” in color in Tehama County, California. <br />
<br />
==Care and Maintenance==<br />
Pectolite can be decomposed by mineral acids into a colorless silica gel; care should be exercised in the use of chemical cleaning agents.<br />
<br />
==Sources==<br />
<br />
*Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona<br />
<br />
*Kunz, George Fredreick (1892) Gems and Precious Stones of North America. The Scientific Publishing Company, New York NY ISBN 0486218554<br />
<br />
*Palache, Charles, Harry Berman & Clifford Frondel (1944): The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition<br />
<br />
*Woodruff, Robert B and Fritsch, Emmanuel (1989) Gems and Gemology, Vol. 25 No. 4 pp 216-225 "Blue Pectolite From The Domininican Republic"<br />
External Links:</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Willemite&diff=5418Willemite2007-01-18T20:45:55Z<p>Russell: </p>
<hr />
<div>{{Willemite}}<br />
<br />
Willemite was named after King Willem (William) the first (1772-1843) of The Netherlands.<br />
<br />
==Crystal Habit==<br />
crystals are long to short prismatic, to 10cm in length. Also fine to coarse granular massive.<br />
<br />
==Chemical Composition==<br />
Zinc silicate, Zn2Si04 . Minor to trace amounts of iron, aluminum, manganese, calcium and magnesium may be present.<br />
<br />
==Diagnostics==<br />
<br />
Yellow to yellow-green shades of willemite can be confused with golden beryl (which possesses a lower refractive index at 1.570 - 1.575, is harder at 7.5 to 8, and has a lower specific gravity of 2.72), and chrysoberyl (which is harder at 8.5, has a higher specific gravity 3.73, and a higher refractive index at 1.746 – 1.755)<br />
<br />
===Color=== <br />
Transparent rough is colorless to golden yellow, pale blue-green. A canary-yellow variety of willemite from Tsumeb, Namibia has been documented, with the color attributed to cadmium (although whether the cadmium is present at a substitute for an essential component, or as finely divided greenockite – cadmium sulfide – is uncertain). Massive material cut en cabochon may be white, apple green, amethystine, yellow to golden brown, grayish, brown. An opaque flesh-red variety is called “troostite” which consists of exsolution laminae of willemite in tephroite, a manganese silicate. <br />
<br />
===Magnification===<br />
may exhibit black inclusions of franklinite, an iron manganese zinc oxide.<br />
<br />
===Specific Gravity===<br />
3.89 – 4.19, sinks in all usual heavy liquids.<br />
<br />
===Refractive Index===<br />
nω = 1.691 – 1.694 , nε = 1.719 – 1.725<br />
<br />
==Treatments==<br />
There are reports that some rough has been heat treated to convert it from colorless to blue. <br />
<br />
==Phenomenon==<br />
<br />
The willemite from Franklin and Ogdensburg, Sussex County, New Jersey commonly fluoresces a brilliant green under Short Wave ultraviolet. It also commonly is phosphorescent, with some specimens continuing to luminesce for hours after excitation has terminated; triboluminscence (luminescence when the specimen is abraded or broken) has been observed. Willemite with a butter-yellow fluorescence has been observed but is uncommon at both Franklin and Ogdensburg. Fluorescent response in Namibian willemite appears to be more erratic in its presence or absence, and tends to be yellow under Short Wave ultraviolet radiation and yellow to orange under Long Wave. Fluorescence must not be considered diagnostic; non-fluorescent willemite has been observed. The “troostite” variety may appear as homogenous willemite in white light, but can exhibit thin lines or streaks of fluorescent green in a non-fluorescent groundmass.<br />
<br />
==Synthetics==<br />
None known<br />
<br />
==Imitations==<br />
None known<br />
<br />
==Occurence==<br />
<br />
Willemite occurs as a primary and secondary mineral in metamorphosed zinc ore deposits. It is uncommon, except at the zinc mines of Franklin and Ogdensburg in Sussex County, New Jersey, where it is one of the three primary ore minerals. Enormous tonnages were mined between circa 1830 and circa 1980. In the late 19th century, one crystal recovered yielded enough rough to cut several stones; the largest faceted stone was 8 carats and became part of the Frederick A. Canfield collection. Of willemite as a gemstone, Dunn (1995) writes: “Willemite has been cut as an uncommon, exotic gem. Fine-quality gemstones have been cut from orange-yellow willemite crystals: gems of 11.1 and 11.7 carats are in the Smithsonian Institution; one of 36.93 carats is in the Harvard Mineralogical Museum; and one of 6.28 carats is in the American Museum of Natural History in New York. Massive material may be quite clean internally and translucent and has provided some gemmy material for the cutting of cabochons.”Facet-grade willemite has also been recovered from the Tsumeb (Tsumcorp) Mine in Tsumeb, Namibia.<br />
<br />
<br />
==Care and Maintenance==<br />
<br />
Willemite can be decomposed by mineral acids into a colorless silica gel; care should be exercised in the use of chemical cleaning agents.<br />
<br />
==Sources==<br />
<br />
*Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona<br />
<br />
*Dunn, Pete J. (1995) Franklin and Sterling Hill, New Jersey: the world’s most magnificent mineral deposits <br />
<br />
*Palache, C. (1935), Minerals of Franklin and Sterling Hill, New Jersey, USG Professional Paper 180<br />
<br />
*Palache, Charles, Harry Berman & Clifford Frondel (1944): The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Template:Pectolite&diff=5396Template:Pectolite2007-01-18T13:51:36Z<p>Russell: </p>
<hr />
<div>{| align=right width=250px {{table}}<br />
|-<br />
! colspan=2 | Pectolite<br />
|-<br />
| Chemical composition || NaCa<sub>2</sub>Si<sub>3</sub>O<sub>8</sub>(OH)<br />
|-<br />
| Crystal system || Triclinic<br />
|-<br />
| Habit || Aggregate<br />
|-<br />
| Cleavage || perfect<br />
|-<br />
| Fracture || uneven<br />
|-<br />
| Hardness || 5<br />
|-<br />
| Optic nature || Biaxial +<br />
|-<br />
| Refractive index || 1.59 - 1.63<br />
|- <br />
| Birefringence || 0.028-0.038<br />
|-<br />
| Dispersion || Very weak<br />
|- <br />
| Specific gravity || 2.62 - 2.87<br />
|-<br />
| Lustre || Silky<br />
|-<br />
| Fluorescence || Green (SW & LW-UV)<br />
|}</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Template:Willemite&diff=5395Template:Willemite2007-01-18T13:48:10Z<p>Russell: </p>
<hr />
<div>{| align=right width=250px {{table}}<br />
|-<br />
! colspan=2 | Willemite<br />
|-<br />
| Chemical composition || Zn<sub>2</sub>SiO<sub>4</sub><br />
|-<br />
| Crystal system || Trigonal<br />
|-<br />
| Habit || prismatic; massive<br />
|-<br />
| Cleavage || indistinct<br />
|-<br />
| Fracture || Conchoidal to irregular<br />
|-<br />
| Hardness || 5.5<br />
|-<br />
| Optic nature || Uniaxial +<br />
|-<br />
| Refractive index || 1.691 - 1.725<br />
|- <br />
| Birefringence || n d<br />
|-<br />
| Dispersion || n d<br />
|- <br />
| Specific gravity || 3.89 - 4.19<br />
|-<br />
| Lustre || Vitreous to resinous<br />
|-<br />
| Fluorescence || green to yellow<br />
|}</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Template:Zincite&diff=5394Template:Zincite2007-01-18T13:40:04Z<p>Russell: </p>
<hr />
<div>{| align=right width=250px {{table}}<br />
|-<br />
! colspan=2 | Zincite<br />
|-<br />
| Chemical composition || (Zn,Mn)0<br />
|-<br />
| Crystal system || Hexagonal<br />
|-<br />
| Habit || Pyramidal (hemihedral); massive<br />
|-<br />
| Cleavage || Perfect on {10-10}; Parting on {0001}<br />
|-<br />
| Fracture || Conchoidal<br />
|-<br />
| Hardness || 4<br />
|-<br />
| Optic nature || Uniaxial +<br />
|-<br />
| Refractive index || 2.013 – 2.029<br />
|- <br />
| Specific gravity || 5.66<br />
|-<br />
| Lustre || Sub-adamantine to resinous<br />
|-<br />
| Fluorescence || Pale yellow (extremely rare)<br />
|}</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Larimar&diff=5379Larimar2007-01-18T06:16:45Z<p>Russell: </p>
<hr />
<div>{{Larimar}}<br />
<br />
A blue pectolite found in the Dominican Republic. See [[pectolite]]<br />
<br />
==Acknowledgements and External Links==<br />
<br />
''Gems & Gemology, Winter 1989 Issue'' [http://www.gia.edu/gemsandgemology/18578/1405/402/back_issue_article_detail.cfm Larimar]<br><br />
[http://www.larimarsource.com/articlepg1.htm Blue Pectolite from the Caribbean]</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Willemite&diff=5378Willemite2007-01-18T06:15:48Z<p>Russell: /* Phenomenon */</p>
<hr />
<div>==Crystal Habit==<br />
crystals are long to short prismatic, to 10cm in length. Also fine to coarse granular massive.<br />
<br />
==Chemical Composition==<br />
Zinc silicate, Zn2Si04 . Minor to trace amounts of iron, aluminum, manganese, calcium and magnesium may be present.<br />
<br />
==Diagnostics==<br />
<br />
Yellow to yellow-green shades of willemite can be confused with golden beryl (which possesses a lower refractive index at 1.570 - 1.575, is harder at 7.5 to 8, and has a lower specific gravity of 2.72), and chrysoberyl (which is harder at 8.5, has a higher specific gravity 3.73, and a higher refractive index at 1.746 – 1.755)<br />
<br />
===Color=== <br />
Transparent rough is colorless to golden yellow, pale blue-green. A canary-yellow variety of willemite from Tsumeb, Namibia has been documented, with the color attributed to cadmium (although whether the cadmium is present at a substitute for an essential component, or as finely divided greenockite – cadmium sulfide – is uncertain). Massive material cut en cabochon may be white, apple green, amethystine, yellow to golden brown, grayish, brown. An opaque flesh-red variety is called “troostite” which consists of exsolution laminae of willemite in tephroite, a manganese silicate. <br />
<br />
===Magnification===<br />
may exhibit black inclusions of franklinite, an iron manganese zinc oxide.<br />
<br />
==Optical and Physical Properties==<br />
<br />
===Cleavage===<br />
indistinct<br />
<br />
===Fracture===<br />
conchoidal to irregular<br />
<br />
===Specific Gravity===<br />
3.89 – 4.19<br />
<br />
===Hardness===<br />
5.5<br />
<br />
===Lustre===<br />
Vitreous to resinous<br />
<br />
===Crystal System===<br />
Hexagonal (trigonal)<br />
<br />
===Optical Nature===<br />
Uniaxial (+)<br />
<br />
===Refractive Index===<br />
nω = 1.691 – 1.694 , nε = 1.719 – 1.725<br />
<br />
==Treatments==<br />
There are reports that some rough has been heat treated to convert it from colorless to blue. <br />
<br />
==Phenomenon==<br />
<br />
The willemite from Franklin and Ogdensburg, Sussex County, New Jersey commonly fluoresces a brilliant green under Short Wave ultraviolet. It also commonly is phosphorescent, with some specimens continuing to luminesce for hours after excitation has terminated; triboluminscence (luminescence when the specimen is abraded or broken) has been observed. Willemite with a butter-yellow fluorescence has been observed but is uncommon at both Franklin and Ogdensburg. Fluorescent response in Namibian willemite appears to be more erratic in its presence or absence, and tends to be yellow under Short Wave ultraviolet radiation and yellow to orange under Long Wave. Fluorescence must not be considered diagnostic; non-fluorescent willemite has been observed. The “troostite” variety may appear as homogenous willemite in white light, but can exhibit thin lines or streaks of fluorescent green in a non-fluorescent groundmass.<br />
<br />
==Synthetics==<br />
None known<br />
<br />
==Imitations==<br />
None known<br />
<br />
==Occurence==<br />
<br />
Willemite occurs as a primary and secondary mineral in metamorphosed zinc ore deposits. It is uncommon, except at the zinc mines of Franklin and Ogdensburg in Sussex County, New Jersey, where it is one of the three primary ore minerals. Enormous tonnages were mined between circa 1830 and circa 1980. In the late 19th century, one crystal recovered yielded enough rough to cut several stones; the largest faceted stone was 8 carats and became part of the Frederick A. Canfield collection. Facet-grade willemite has also been recovered from the Tsumeb (Tsumcorp) Mine in Tsumeb, Namibia.<br />
<br />
Of willemite as a gemstone, Dunn (1995) writes: “Willemite has been cut as an uncommon, exotic gem. Fine-quality gemstones have been cut from orange-yellow willemite crystals: gems of 11.1 and 11.7 carats are in the Smithsonian Institution; one of 36.93 carats is in the Harvard Mineralogical Museum; and one of 6.28 carats is in the American Museum of Natural History in New York. Massive material may be quite clean internally and translucent and has provided some gemmy material for the cutting of cabochons.”<br />
<br />
==Care and Maintenance==<br />
<br />
Willemite can be decomposed by mineral acids into a colorless silica gel; care should be exercised in the use of chemical cleaning agents.<br />
<br />
==Sources==<br />
<br />
*Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona<br />
<br />
*Dunn, Pete J. (1995) Franklin and Sterling Hill, New Jersey: the world’s most magnificent mineral deposits <br />
<br />
*Palache, C. (1935), Minerals of Franklin and Sterling Hill, New Jersey, USG Professional Paper 180<br />
<br />
*Palache, Charles, Harry Berman & Clifford Frondel (1944): The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Pectolite&diff=5376Pectolite2007-01-18T05:51:54Z<p>Russell: </p>
<hr />
<div>Pectolite<br />
<br />
Varietal Names: “Larimar” is a blue pectolite from the Dominican Republic; the name “Larimar”is trademarked. <br />
<br />
Crystal System: Triclinic<br />
<br />
Crystal Habit: Crystals are uncommon and are usually tabular. More commonly occurs as bundles of acicular needles showing either columnar or radiating fibrous structure.<br />
<br />
Composition: sodium calcium silicate hydroxide, NaCa2Si308(OH). Minor to trace amounts of iron, potassium and copper may be present. <br />
<br />
Diagnostics:<br />
<br />
Color: Colorless, white, pale apple green, dark green; the Larimar variety varies from white to light medium blue (similar to turquoise) to green.<br />
<br />
Magnification:<br />
The “Larimar” type of pectolite displays opaque red dendritic hematite, inclusions of translucent to transparent square patches of calcite to 2 mm wide, sprays of transparent to translucent grey natrolite as long prisms with square cross section, opaque blebs of native copper, and opaque blebs and euhedral crystals of chalcocite, a copper sulfide Woodruff (1989). This same assemblage of accessory minerals is present in other, non-gem quality pectolite occurrences, such as the basalts of Paterson, New Jersey. <br />
<br />
Optical and Physical Properties:<br />
<br />
Cleavage: perfect on {100} and {001}. <br />
<br />
Fracture: Uneven<br />
<br />
Specific Gravity: 2.84 to 2.90 (measured) 2.97 (calculated). Measurements of the specific gravity of Larimar ranged from 2.62 to 2.87; low range readings were probably a result of a inclusions of other minerals in the pectolite. <br />
<br />
Hardness: 4.5 to 5.0<br />
<br />
Lustre: silky, subvitreous<br />
<br />
Optical Nature: Biaxial (+)<br />
<br />
Refractive Index: α = 1.592 – 1.610, β = 1.603 to 1.615, γ = 1.630 – 1.645<br />
<br />
Birefringence: <br />
<br />
Dispersion: <br />
<br />
Pleochroism:<br />
<br />
Spectroscope:<br />
<br />
Fluorescence: Woodruff and Fritsch (1989) report a turbid green fluorescence under Short Wave ultraviolet radiation and a chalky green fluorescence under Long Wave. <br />
<br />
Phenomenon: Larimar may exhibit localized areas that appear chatoyant resulting from oriented parallel clusters of pectolite needles.<br />
<br />
Treatments:<br />
<br />
Synthetics:<br />
<br />
Imitations:<br />
<br />
Occurence: <br />
<br />
Occurs in cavities in basalts and diabases as a result of hydrothermal action.<br />
<br />
The Larimar variety of pectolite occurs in a basalt formation about 5km west of Baoruco, Dominican Republic; the pectolite was first discovered in 1974 as stream-rounded pebbles in an adjacent river.<br />
<br />
In 1884, Frank W Clarke reported that a number of Eskimo artifacts collected near Point Barrow, Alaska – originally believed to be jade - were, in fact, composed of a “interesting variety of compact pectolite, in two varieties, one pale apple green, the other dark green” [cited in Kunz (1892)]. Apparently the original source of the pectolite has not been found. Kunz also notes in 1887 geologist William P. Blake reported the discovery of a significant occurrence of compact, translucent pectolite that was “white, with a delicate shade of sea green” in color in Tehama County, California. <br />
<br />
Care and Maintenance: Pectolite can be decomposed by mineral acids into a colorless silica gel; care should be exercised in the use of chemical cleaning agents.<br />
<br />
Sources:<br />
<br />
Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona<br />
<br />
Kunz, George Fredreick (1892) Gems and Precious Stones of North America. The Scientific Publishing Company, New York NY ISBN 0486218554<br />
<br />
Palache, Charles, Harry Berman & Clifford Frondel (1944): The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition<br />
<br />
Woodruff, Robert B and Fritsch, Emmanuel (1989) Gems and Gemology, Vol. 25 No. 4 pp 216-225 "Blue Pectolite From The Domininican Republic"<br />
External Links:</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Table_Of_Contents&diff=5375Table Of Contents2007-01-18T05:45:40Z<p>Russell: </p>
<hr />
<div>In this TOC (Table Of Contents) you will find pages that have been published presented in blue and pages that yet need to be written presented in red. For better navigation, we list the pages in 3 categories:<br />
#Theory - Basic and in-depth mechanisms involved in gemology<br />
#Practical - Descriptions of instruments, techniques and other practical discussions<br />
#Gemstones - Information about the gemstone at hand<br />
<br />
For the neophyte it is best to start in that order as some words and principles introduced in the theory pages will need to be understood first. At the very least, one should learn the theory in the "basic" sections of the pages.<br /><br />
Although gemology is not rocket science, some science and math is involved. We don't believe in the dumbing-down of gemology, so you should be ready and willing to expand your horizons. If you find any of the technical concepts difficult to visualize or grasp, go to the forum (the link is above) and ask. We will help you with it, and at the same time you will help this project become more complete for those who come after you. <br />
<br />
We never said it was going to be easy. But it's a heck of an interesting ride.<br />
<br />
<br />
{| {{toctable}} width="100%"<br />
<br />
!Theory <br />
!Practical<br />
!Gemstones<br />
<br />
|-<br />
<br />
|style="padding-right:5px" valign="top"|<br />
:'''Content'''<br />
#[[Introduction to Gemology]]<br />
##[[Introduction_to_Gemology#Education|Education]]<br />
##[[An Historical Look at our Obsession with Gems]]<br />
##[[Glossary of Terms]]<br />
#[[Origins of minerals]]<br />
##[[Origins_of_minerals#Igneous_.28Magmatic.29_rocks|Igneous rocks]]<br />
##[[Origins_of_minerals#Sedimentary_rocks|Sedimentary rocks]]<br />
##[[Origins_of_minerals#Metamorphic_rocks|Metamorphic rocks]]<br />
#[[The Chemistry of Gemstones]]<br />
##[[Isomorphous replacement]]<br />
##[[The Chemical Classification of Gems & Minerals]]<br />
#[[Crystallography]]<br />
##[[Crystal Systems]]<br />
##[[Form]]<br />
##[[Habit]]<br />
##[[Symmetry]]<br />
##[[Twinning]]<br />
#[[Cleavage]]<br />
#[[Cleavage#Parting|Parting]]<br />
#[[Cleavage#Fracture|Fracture]]<br />
#[[Optical properties of gemstones]]<br />
##[[Nature of light]]<br />
###[[Nature_of_light#The_electromagnetic_wave_theory |The electromagnetic wave theory]]<br />
###[[Nature_of_light#The_quantum_theory |The quantum theory]]<br />
###[[Nature_of_light#The_electromagnetic_spectrum |The electromagnetic spectrum]]<br />
##[[Reflection effects]]<br />
###[[Luster]]<br />
###[[Sheen]]<br />
####[[Sheen#Chatoyancy | Chatoyancy]]<br />
####[[Sheen#Asterism | Asterism]]<br />
####[[Sheen#Iridescence | Iridescence]]<br />
###[[Brilliance | Brilliance (Total Internal Reflection)]]<br />
##[[Polarization]]<br />
##[[Pleochroism]]<br />
##[[Color]]<br />
###[[Causes of color]]<br />
##[[Refraction]]<br />
###[[Double Refraction]]<br />
##[[Dispersion]]<br />
##[[Diffraction]]<br />
##[[Interference]]<br />
##[[Luminescence]]<br />
###[[Luminescence#Fluorescence | Fluorescence]]<br />
###[[Luminescence#Phosphorescence | Phosphorescence]]<br />
###[[Luminescence#Tenebrescence | Tenebrescence]]<br />
###[[Luminescence#Triboluminescence | Triboluminescence]]<br />
#[[Hardness]]<br />
#[[Specific Gravity]]<br />
#[[Math| Basic math for gemology]]<br />
##[[Math#Cross-multiplication | Cross-multiplication]]<br />
##[[Math#Sine.2C_cosine_and_tangent | Sine, cosine and tangent]]<br />
##[[Math#Degrees.2C_minutes_and_seconds | Degrees, minutes and seconds]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
#[[Equipment used to identify gemstones]]<br />
##[[10x Loupe]]<br />
##[[Spectroscope]]<br />
##[[Refractometer]]<br />
##[[Polariscope]]<br />
##[[Dichroscope]]<br />
##[[Immersion Cell]]<br />
##[[Color Filters]]<br />
##[[Microscope]]<br />
##[[Hydrostatic Balance]]<br />
##[[Heavy Liquids]]<br />
##[[Hardness#Hardness_pencils|Hardness pencils]]<br />
#[[Inclusions]]<br />
#[[Synthetic gemstones]]<br />
#[[Visual Optics]]<br />
##[[The Hodgkinson Method]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
*[[Alphabetic list by gemstone name]]<br />
#[[Diamond]]<br />
#[[Corundum]]<br />
##[[Ruby]]<br />
##[[Sapphire]]<br />
#[[Beryl]]<br />
##[[Aquamarine]]<br />
##[[Bixbite]]<br />
##[[Emerald]]<br />
###[[Vanadium Beryl]]<br />
##[[Goshenite]]<br />
##[[Green Beryl]]<br />
##[[Heliodor]]<br />
##[[Maxixe]]<br />
##[[Morganite]]<br />
##[[Riesling]]<br />
##[[True Blue]]<br />
##[[Pezzottaite]] (Beryl Group)<br />
#[[Quartz]]<br />
##[[Amethyst]]<br />
##[[Ametrine]]<br />
##[[Citrine]]<br />
##[[Prasiolite]]<br />
##[[Rock Crystal]]<br />
##[[Rose Quartz]]<br />
##[[Smokey Quartz]]<br />
#[[Quartz - Microcrystalline]]<br />
##[[Chalcedony]]<br />
###[[Agate]]<br />
###[[Bloodstone]]<br />
###[[Carnelian]]<br />
###[[Chrysoprase]]<br />
###[[Jasper]]<br />
###[[Onyx]]<br />
###[[Sard]]<br />
###[[Sardonyx]]<br />
###[[Tigereye]]<br />
#[[Zoisite]]<br />
##[[Tanzanite]]<br />
##[[Thulite]]<br />
#[[Garnet]]<br />
##[[Almandine]]<br />
##[[Andradite]]<br />
###[[Andradite#Demantoid|Demantoid]]<br />
##[[Grossular]]<br />
###[[Grossular#Chrome_grossular|Chrome grossular]]<br />
###[[Grossular#Hessonite|Hessonite]]<br />
###[[Grossular#Hydrogrossular |Hydrogrossular]]<br />
###[[Grossular#Mali|Mali]]<br />
###[[Grossular#Tsavorite|Tsavorite]]<br />
##[[Pyrope]]<br />
##[[Spessartite]]<br />
##[[Uvarovite]]<br />
#[[Diopside]]<br />
##[[Chrome Diopside]]<br />
##[[Tashmarine]]&trade;<br />
#[[Feldspar]]<br />
##[[Amazonite]]<br />
##[[Andesine]]<br />
##[[Labradorite]]<br />
##[[Moonstone]]<br />
##[[Spectrolite]]<br />
##[[Sunstone]]<br />
#[[Spodumene]]<br />
##[[Hiddenite]]<br />
##[[Kunzite]]<br />
#[[Chrysoberyl]]<br />
##[[Alexandrite]]<br />
#[[Spinel]]<br />
#[[Tourmaline]]<br />
##[[Achroite]]<br />
##[[Bi-color]]<br />
##[[Chrome]]<br />
##[[Dravite]]<br />
##[[Indicolite]]<br />
##[[Liddicoatite]]<br />
##[[Paraiba type]]<br />
##[[Rubellite]]<br />
##[[Schorl]]<br />
##[[Tri-Color]]<br />
##[[Verdite]]<br />
##[[Watermelon]]<br />
#[[Amber]]<br />
#[[Ammolite]]<br />
#[[Anatase]]<br />
#[[Andalusite]]<br />
#[[Apatite]]<br />
#[[Benitoite]]<br />
#[[Bowenite]]<br />
#[[Californite]]<br />
#[[Charoite]]<br />
#[[Chrysocolla]]<br />
#[[Coral]]<br />
#[[Cyprine]]<br />
#[[Danburite]]<br />
#[[Datolite]]<br />
#[[Dioptase]]<br />
#[[Enstatite]]<br />
#[[Fluorite]]<br />
#[[Glass]]<br />
##[[Goldstone]]<br />
#[[Hauyne]]<br />
#[[Iolite]]<br />
#[[Jade]]<br />
##[[Jadeite]]<br />
##[[Nephrite]]<br />
#[[Kornerupine]]<br />
#[[Lapis Lazuli]]<br />
#[[Larimar]]<br />
#[[Maw-sit-sit]]<br />
#[[Opal]]<br />
##[[Black Opal]]<br />
##[[Blue Peruvian Opal]]<br />
##[[Boulder Opal]]<br />
##[[Fire Opal]]<br />
#[[Pearl]]<br />
##[[Salt water]]<br />
###[[Akoya]]<br />
###[[Tahitian]]<br />
###[[South Sea]]<br />
###[[Mabé]]<br />
###[[Conch Pearl]]<br />
###[[Melo Pearl]]<br />
###[[Quahog]]<br />
##[[Freshwater Pearl]]<br />
###[[Kasumiga pearls]]<br />
###[[Chinese freshwater pearls]]<br />
#[[Pectolite]]<br />
#[[Peridot]]<br />
#[[Poudretteite]]<br />
#[[Scapolite]]<br />
#[[Sodalite]]<br />
##[[Hackmanite]]<br />
#[[Sphalerite]]<br />
#[[Sphene]]<br />
#[[Topaz]]<br />
#[[Turquoise]]<br />
#[[Vesuvianite]]<br />
#[[Willemite]]<br />
#[[Zincite]]<br />
#[[Zircon]]<br />
|}</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Vesuvianite&diff=5372Vesuvianite2007-01-18T03:57:28Z<p>Russell: </p>
<hr />
<div>{{Vesuvianite}}<br />
<br />
[[Image:Vesuvianite.JPG|left|framed|Faceted vesuvianite]]<br clear="left" /><br />
<br />
Vesuvianite <br />
<br />
Synonyms: Idocrase<br />
<br />
Vesuvianite takes its name from Mount Vesuvius, the famed volcano in Italy, where the mineral was first found; it was named in 1795 by the famous mineralogist Abraham Gottlob Werner. The French mineralogist Rene Just Hauy suggested it should be named Idocrase four years later. Werner’s name takes precedence. <br />
<br />
Variental Names: Cyprine, Californite<br />
<br />
Cyprine is a blue copper containing variety of vesuvianite that was first described from Norway about 1821 by the famous mineralogist Berzelius; the name is derived from Cyprium, the ancient term for copper. <br />
<br />
Californite is a compact massive form of vesuvianite that has an appearance to poor quality jade. It has historically be used as a jade simulant. It was first described by famed gemologist George Frederick Kunz in 1903, who suggested the name “californite” in honor of the state in which it was found. Dietrich (2005) offered the following opinion: “With all due regards to G.F. Kunz, I believe that… vesuvianite would have gained more "prestige" in gemology if the term californite had never been introduced.” He added “…the use of any gem material as a simulant serves only to denigrate its use under its own name.” Californite has also been called “American Jade”, “California Jade”, and “Vesuvianite Jade”. Any usage of names for vesuvianite which include “jade” should be discouraged. <br />
<br />
Crystal System: tetragonal or monoclinic<br />
<br />
Crystal Habit: prismatic to equant stubby crystals; massive granular to fine grained.<br />
<br />
Composition: Ca10Mg2Al4(SiO4)5(Si2O7)2(OH)4 often containing trace to minor amounts of iron, copper up to 2.1% as Cu in cyprine), chromium, manganese, titanium, boron or beryllium.<br />
<br />
Diagnostics:<br />
<br />
Peridot has a lower refractive index (1.654 to 1.670).The californite variety of vesuvianite floats or sinks slowly in methylene iodide; jadeite sinks (specific gravity less than 3.3). Nephrite has a lower specific gravity (3.295). <br />
<br />
Color: yellow, yellowish green, green, emerald green, yellow brown, brown, blue, violet to magneta; sometimes displays distinct color zoning.<br />
<br />
Magnification:<br />
<br />
Under magnification, the cyprine variety may exhibit a distinctly fibrous appearance.<br />
<br />
Optical and Physical Properties:<br />
<br />
Cleavage: poor on {110}, {100} and very poor on {001}<br />
<br />
Fracture: subconcoidal to uneven<br />
<br />
Specific Gravity: 3.32 - 3.34 (measured); 3.42 (calculated)<br />
<br />
Hardness: 6 to 7<br />
<br />
Lustre: Vitreous to resinous<br />
<br />
Optical Nature: Uniaxial (+) or Uniaxial (-); biaxial vesuvianite has been observed.<br />
<br />
Refractive Index: ω = 1.703 – 1.752 ε = 1.700 – 1.746. The variety cyprine from Franklin New Jersey demonstrates a lower range of refractive indices, with ω = 1.696 – 1.712 ε = 1.710 – 1.719. <br />
<br />
Birefringence: approximately 0.005<br />
<br />
Dispersion: strong<br />
<br />
Pleochroism: weak; O = colorless to yellowish, E = yellowish, greenish, brownish<br />
<br />
Spectroscope:<br />
<br />
Treatments: <br />
<br />
Phenomenon:<br />
<br />
Synthetics: none<br />
<br />
Imitations:<br />
<br />
Occurence:<br />
<br />
Vesuvianite usually results from contact or regional metamorphism of limestones containing silica. <br />
<br />
The Jeffrey Mine in Asbestos, Quebec has afforded facet rough that is predominantly yellow-green in color, similar to peridot; the mine has also produced an emerald green chrome-bearing vesuvianite and a violet to magenta manganoan vesuvianite that is sometimes called “manganovesuvianite” (this term is too close to the name of a different, non-gem mineral species, “manganvesuvianite” for comfort and should be discouraged). Bicolored facetted stones consisting of yellow-green common vesuvianite on one side, and pale magenta manganoan vesuvianite on the other, have been cut. Italy – most notably Bellecombe in Val d’Aosta has produced greenish brown to brown faceting rough. During the past decade, Fushan, Hebei Province, China has produced moderate quantities of deep yellow-brown (sometimes called “root beer”) colored crystals with gemmy areas capable of being facetted and cut en cabochon. Kaiiado District, Rift Valley Province, Kenya has produced greenish yellow to yellowish green vesuvianite faceting rough. <br />
<br />
Cyprine - The original Norwegian find was of no interest as a gem material, but a significant quantity of cyprite was uncovered in 1922 during mining at Franklin, New Jersey, about 850 feet underground. Reports have been made of facetted specimens of cyprine from Sri Lanka, Jakobsberg Mine, Värmland, Sweden, and Pakistan; all are a pale blue tinged with grey. <br />
<br />
Californite - Northern California has produced Californite at several locations, including Happy Camp in Siskyou County, the Pulga Deposit on the North Fork of the Feather River, Butte County, and Tulare County.<br />
<br />
Sources:<br />
<br />
Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona<br />
<br />
Dietrich, R. V. (2005): “Vesuvianite” (webpage at: http://www.cst.cmich.edu/users/dietr1rv/vesuvianite.htm)<br />
<br />
Kunz, George Frederick (1903), American Journal of Science, 4th. Series, Vol. 16 pp397-398 “Californite (vesuvianite); a new ornamental stone”<br />
Palache, Charles, Harry Berman & Clifford Frondel (1944): The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition <br />
Shannon, E. V. (1922) Note on the cyprine from Franklin Furnace, New Jersey. American Mineralogist, 7, 140-142. <br />
<br />
External Links:</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Vesuvianite&diff=5371Vesuvianite2007-01-18T03:51:11Z<p>Russell: </p>
<hr />
<div>{{Vesuvianite}}<br />
<br />
[[Image:Vesuvianite.JPG|left|framed|Faceted vesuvianite]]<br clear="left" /><br />
<br />
Vesuvianite <br />
<br />
Synonyms: Idocrase<br />
<br />
Vesuvianite takes its name from Mount Vesuvius, the famed volcano in Italy, where the mineral was first found; it was named in 1795 by the famous mineralogist Abraham Gottlob Werner. The French mineralogist Rene Just Hauy suggested it should be named Idocrase four years later. Werner’s name takes precedence. <br />
<br />
Variental Names: Cyprine, Californite<br />
<br />
Cyprine is a blue copper containing variety of vesuvianite that was first described from Norway about 1821 by the famous mineralogist Berzelius; the name is derived from Cyprium, the ancient term for copper. <br />
<br />
Californite is a compact massive form of vesuvianite that has an appearance to poor quality jade. It has historically be used as a jade simulant. It was first described by famed gemologist George Frederick Kunz in 1903, who suggested the name “californite” in honor of the state in which it was found. Dietrich (2005) offered the following opinion: “With all due regards to G.F. Kunz, I believe that… vesuvianite would have gained more "prestige" in gemology if the term californite had never been introduced.” He added “…the use of any gem material as a simulant serves only to denigrate its use under its own name.” Californite has also been called “American Jade”, “California Jade”, and “Vesuvianite Jade”. Any usage of names for vesuvianite which include “jade” should be discouraged. <br />
<br />
Crystal System: tetragonal or monoclinic<br />
<br />
Crystal Habit: prismatic to equant stubby crystals; massive granular to fine grained.<br />
<br />
Composition: Ca10Mg2Al4(SiO4)5(Si2O7)2(OH)4 often containing trace to minor amounts of iron, copper up to 2.1% as Cu in cyprine), chromium, manganese, titanium, boron or beryllium.<br />
<br />
Diagnostics:<br />
<br />
Peridot has a lower refractive index (1.654 to 1.670).The californite variety of vesuvianite floats or sinks slowly in methylene iodide; jadeite sinks (specific gravity less than 3.3). Nephrite has a lower specific gravity (3.295). <br />
<br />
Color: yellow, yellowish green, green, emerald green, yellow brown, brown, blue, violet to magneta; sometimes displays distinct color zoning.<br />
<br />
Magnification:<br />
<br />
Under magnification, the cyprine variety may exhibit a distinctly fibrous appearance.<br />
<br />
Optical and Physical Properties:<br />
<br />
Cleavage: poor on {110}, {100} and very poor on {001}<br />
<br />
Fracture: subconcoidal to uneven<br />
<br />
Specific Gravity: 3.32 - 3.34 (measured); 3.42 (calculated)<br />
<br />
Hardness: 6 to 7<br />
<br />
Lustre: Vitreous to resinous<br />
<br />
Optical Nature: Uniaxial (+) or Uniaxial (-); biaxial vesuvianite has been observed.<br />
<br />
Refractive Index: ω = 1.703 – 1.752 ε = 1.700 – 1.746. The variety cyprine from Franklin New Jersey demonstrates a lower range of refractive indices, with ω = 1.696 – 1.712 ε = 1.710 – 1.719. <br />
<br />
Birefringence: approximately 0.005<br />
<br />
Dispersion: strong<br />
<br />
Pleochroism: weak; O = colorless to yellowish, E = yellowish, greenish, brownish<br />
<br />
Spectroscope:<br />
<br />
Treatments: <br />
<br />
Phenomenon:<br />
<br />
Synthetics: none<br />
<br />
Imitations:<br />
<br />
Occurence:<br />
<br />
The Jeffrey Mine in Asbestos, Quebec has afforded facet rough that is predominantly yellow-green in color, similar to peridot; the mine has also produced an emerald green chrome-bearing vesuvianite and a violet to magenta manganoan vesuvianite that is sometimes called “manganovesuvianite” (this term is too close to the name of a different, non-gem mineral species, “manganvesuvianite” for comfort and should be discouraged). Bicolored facetted stones consisting of yellow-green common vesuvianite on one side, and pale magenta manganoan vesuvianite on the other, have been cut. Italy – most notably Bellecombe in Val d’Aosta has produced greenish brown to brown faceting rough. During the past decade, Fushan, Hebei Province, China has produced moderate quantities of deep yellow-brown (sometimes called “root beer”) colored crystals with gemmy areas capable of being facetted and cut en cabochon. Kaiiado District, Rift Valley Province, Kenya has produced greenish yellow to yellowish green vesuvianite faceting rough. <br />
<br />
Cyprine - The original Norwegian find was of no interest as a gem material, but a significant quantity of cyprite was uncovered in 1922 during mining at Franklin, New Jersey, about 850 feet underground. Reports have been made of facetted specimens of cyprine from Sri Lanka, Jakobsberg Mine, Värmland, Sweden, and Pakistan; all are a pale blue tinged with grey. <br />
<br />
Californite - Northern California has produced Californite at several locations, including Happy Camp in Siskyou County, the Pulga Deposit on the North Fork of the Feather River, Butte County, and Tulare County.<br />
<br />
Sources:<br />
<br />
Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona<br />
<br />
Dietrich, R. V. (2005): “Vesuvianite” (webpage at: http://www.cst.cmich.edu/users/dietr1rv/vesuvianite.htm)<br />
<br />
Kunz, George Frederick (1903), American Journal of Science, 4th. Series, Vol. 16 pp397-398 “Californite (vesuvianite); a new ornamental stone”<br />
Palache, Charles, Harry Berman & Clifford Frondel (1944): The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition <br />
Shannon, E. V. (1922) Note on the cyprine from Franklin Furnace, New Jersey. American Mineralogist, 7, 140-142. <br />
<br />
External Links:</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Cyprine&diff=5370Cyprine2007-01-18T03:49:53Z<p>Russell: </p>
<hr />
<div><br />
Cyprine is a blue, copper bearing variety of [[vesuvianite]]</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Cyprine&diff=5369Cyprine2007-01-18T03:49:43Z<p>Russell: </p>
<hr />
<div><br />
<br />
Cyprine is a blue, copper bearing variety of vesuvianite</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Californite&diff=5368Californite2007-01-18T03:49:01Z<p>Russell: </p>
<hr />
<div>Californite is a massive form of [[vesuvianite]], often used as a jade simulant.</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Californite&diff=5367Californite2007-01-18T03:48:36Z<p>Russell: </p>
<hr />
<div><br />
Californite is a massive form of vesuvianite, often used as a jade simulant.</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Table_Of_Contents&diff=5366Table Of Contents2007-01-18T03:47:37Z<p>Russell: </p>
<hr />
<div>In this TOC (Table Of Contents) you will find pages that have been published presented in blue and pages that yet need to be written presented in red. For better navigation, we list the pages in 3 categories:<br />
#Theory - Basic and in-depth mechanisms involved in gemology<br />
#Practical - Descriptions of instruments, techniques and other practical discussions<br />
#Gemstones - Information about the gemstone at hand<br />
<br />
For the neophyte it is best to start in that order as some words and principles introduced in the theory pages will need to be understood first. At the very least, one should learn the theory in the "basic" sections of the pages.<br /><br />
Although gemology is not rocket science, some science and math is involved. We don't believe in the dumbing-down of gemology, so you should be ready and willing to expand your horizons. If you find any of the technical concepts difficult to visualize or grasp, go to the forum (the link is above) and ask. We will help you with it, and at the same time you will help this project become more complete for those who come after you. <br />
<br />
We never said it was going to be easy. But it's a heck of an interesting ride.<br />
<br />
<br />
{| {{toctable}} width="100%"<br />
<br />
!Theory <br />
!Practical<br />
!Gemstones<br />
<br />
|-<br />
<br />
|style="padding-right:5px" valign="top"|<br />
:'''Content'''<br />
#[[Introduction to Gemology]]<br />
##[[Introduction_to_Gemology#Education|Education]]<br />
##[[An Historical Look at our Obsession with Gems]]<br />
##[[Glossary of Terms]]<br />
#[[Origins of minerals]]<br />
##[[Origins_of_minerals#Igneous_.28Magmatic.29_rocks|Igneous rocks]]<br />
##[[Origins_of_minerals#Sedimentary_rocks|Sedimentary rocks]]<br />
##[[Origins_of_minerals#Metamorphic_rocks|Metamorphic rocks]]<br />
#[[The Chemistry of Gemstones]]<br />
##[[Isomorphous replacement]]<br />
##[[The Chemical Classification of Gems & Minerals]]<br />
#[[Crystallography]]<br />
##[[Crystal Systems]]<br />
##[[Form]]<br />
##[[Habit]]<br />
##[[Symmetry]]<br />
##[[Twinning]]<br />
#[[Cleavage]]<br />
#[[Cleavage#Parting|Parting]]<br />
#[[Cleavage#Fracture|Fracture]]<br />
#[[Optical properties of gemstones]]<br />
##[[Nature of light]]<br />
###[[Nature_of_light#The_electromagnetic_wave_theory |The electromagnetic wave theory]]<br />
###[[Nature_of_light#The_quantum_theory |The quantum theory]]<br />
###[[Nature_of_light#The_electromagnetic_spectrum |The electromagnetic spectrum]]<br />
##[[Reflection effects]]<br />
###[[Luster]]<br />
###[[Sheen]]<br />
####[[Sheen#Chatoyancy | Chatoyancy]]<br />
####[[Sheen#Asterism | Asterism]]<br />
####[[Sheen#Iridescence | Iridescence]]<br />
###[[Brilliance | Brilliance (Total Internal Reflection)]]<br />
##[[Polarization]]<br />
##[[Pleochroism]]<br />
##[[Color]]<br />
###[[Causes of color]]<br />
##[[Refraction]]<br />
###[[Double Refraction]]<br />
##[[Dispersion]]<br />
##[[Diffraction]]<br />
##[[Interference]]<br />
##[[Luminescence]]<br />
###[[Luminescence#Fluorescence | Fluorescence]]<br />
###[[Luminescence#Phosphorescence | Phosphorescence]]<br />
###[[Luminescence#Tenebrescence | Tenebrescence]]<br />
###[[Luminescence#Triboluminescence | Triboluminescence]]<br />
#[[Hardness]]<br />
#[[Specific Gravity]]<br />
#[[Math| Basic math for gemology]]<br />
##[[Math#Cross-multiplication | Cross-multiplication]]<br />
##[[Math#Sine.2C_cosine_and_tangent | Sine, cosine and tangent]]<br />
##[[Math#Degrees.2C_minutes_and_seconds | Degrees, minutes and seconds]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
#[[Equipment used to identify gemstones]]<br />
##[[10x Loupe]]<br />
##[[Spectroscope]]<br />
##[[Refractometer]]<br />
##[[Polariscope]]<br />
##[[Dichroscope]]<br />
##[[Immersion Cell]]<br />
##[[Color Filters]]<br />
##[[Microscope]]<br />
##[[Hydrostatic Balance]]<br />
##[[Heavy Liquids]]<br />
##[[Hardness#Hardness_pencils|Hardness pencils]]<br />
#[[Inclusions]]<br />
#[[Synthetic gemstones]]<br />
#[[Visual Optics]]<br />
##[[The Hodgkinson Method]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
*[[Alphabetic list by gemstone name]]<br />
#[[Diamond]]<br />
#[[Corundum]]<br />
##[[Ruby]]<br />
##[[Sapphire]]<br />
#[[Beryl]]<br />
##[[Aquamarine]]<br />
##[[Bixbite]]<br />
##[[Emerald]]<br />
###[[Vanadium Beryl]]<br />
##[[Goshenite]]<br />
##[[Green Beryl]]<br />
##[[Heliodor]]<br />
##[[Maxixe]]<br />
##[[Morganite]]<br />
##[[Riesling]]<br />
##[[True Blue]]<br />
##[[Pezzottaite]] (Beryl Group)<br />
#[[Quartz]]<br />
##[[Amethyst]]<br />
##[[Ametrine]]<br />
##[[Citrine]]<br />
##[[Prasiolite]]<br />
##[[Rock Crystal]]<br />
##[[Rose Quartz]]<br />
##[[Smokey Quartz]]<br />
#[[Quartz - Microcrystalline]]<br />
##[[Chalcedony]]<br />
###[[Agate]]<br />
###[[Bloodstone]]<br />
###[[Carnelian]]<br />
###[[Chrysoprase]]<br />
###[[Jasper]]<br />
###[[Onyx]]<br />
###[[Sard]]<br />
###[[Sardonyx]]<br />
###[[Tigereye]]<br />
#[[Zoisite]]<br />
##[[Tanzanite]]<br />
##[[Thulite]]<br />
#[[Garnet]]<br />
##[[Almandine]]<br />
##[[Andradite]]<br />
###[[Andradite#Demantoid|Demantoid]]<br />
##[[Grossular]]<br />
###[[Grossular#Chrome_grossular|Chrome grossular]]<br />
###[[Grossular#Hessonite|Hessonite]]<br />
###[[Grossular#Hydrogrossular |Hydrogrossular]]<br />
###[[Grossular#Mali|Mali]]<br />
###[[Grossular#Tsavorite|Tsavorite]]<br />
##[[Pyrope]]<br />
##[[Spessartite]]<br />
##[[Uvarovite]]<br />
#[[Diopside]]<br />
##[[Chrome Diopside]]<br />
##[[Tashmarine]]&trade;<br />
#[[Feldspar]]<br />
##[[Amazonite]]<br />
##[[Andesine]]<br />
##[[Labradorite]]<br />
##[[Moonstone]]<br />
##[[Spectrolite]]<br />
##[[Sunstone]]<br />
#[[Spodumene]]<br />
##[[Hiddenite]]<br />
##[[Kunzite]]<br />
#[[Chrysoberyl]]<br />
##[[Alexandrite]]<br />
#[[Spinel]]<br />
#[[Tourmaline]]<br />
##[[Achroite]]<br />
##[[Bi-color]]<br />
##[[Chrome]]<br />
##[[Dravite]]<br />
##[[Indicolite]]<br />
##[[Liddicoatite]]<br />
##[[Paraiba type]]<br />
##[[Rubellite]]<br />
##[[Schorl]]<br />
##[[Tri-Color]]<br />
##[[Verdite]]<br />
##[[Watermelon]]<br />
#[[Amber]]<br />
#[[Ammolite]]<br />
#[[Anatase]]<br />
#[[Andalusite]]<br />
#[[Apatite]]<br />
#[[Benitoite]]<br />
#[[Bowenite]]<br />
#[[Californite]]<br />
#[[Charoite]]<br />
#[[Chrysocolla]]<br />
#[[Coral]]<br />
#[[Cyprine]]<br />
#[[Danburite]]<br />
#[[Datolite]]<br />
#[[Dioptase]]<br />
#[[Enstatite]]<br />
#[[Fluorite]]<br />
#[[Glass]]<br />
##[[Goldstone]]<br />
#[[Hauyne]]<br />
#[[Iolite]]<br />
#[[Jade]]<br />
##[[Jadeite]]<br />
##[[Nephrite]]<br />
#[[Kornerupine]]<br />
#[[Lapis Lazuli]]<br />
#[[Larimar]]<br />
#[[Maw-sit-sit]]<br />
#[[Opal]]<br />
##[[Black Opal]]<br />
##[[Blue Peruvian Opal]]<br />
##[[Boulder Opal]]<br />
##[[Fire Opal]]<br />
#[[Pearl]]<br />
##[[Salt water]]<br />
###[[Akoya]]<br />
###[[Tahitian]]<br />
###[[South Sea]]<br />
###[[Mabé]]<br />
###[[Conch Pearl]]<br />
###[[Melo Pearl]]<br />
###[[Quahog]]<br />
##[[Freshwater Pearl]]<br />
###[[Kasumiga pearls]]<br />
###[[Chinese freshwater pearls]]<br />
#[[Peridot]]<br />
#[[Poudretteite]]<br />
#[[Scapolite]]<br />
#[[Sodalite]]<br />
##[[Hackmanite]]<br />
#[[Sphalerite]]<br />
#[[Sphene]]<br />
#[[Topaz]]<br />
#[[Turquoise]]<br />
#[[Vesuvianite]]<br />
#[[Willemite]]<br />
#[[Zincite]]<br />
#[[Zircon]]<br />
|}</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Vesuvianite&diff=5364Vesuvianite2007-01-18T03:45:10Z<p>Russell: </p>
<hr />
<div>{{Vesuvianite}}<br />
<br />
[[Image:Vesuvianite.JPG|left|framed|Faceted vesuvianite]]<br clear="left" /><br />
<br />
Vesuvianite <br />
<br />
Synonyms: Idocrase<br />
<br />
Vesuvianite takes its name from Mount Vesuvius, the famed volcano in Italy, where the mineral was first found; it was named in 1795 by the famous mineralogist Abraham Gottlob Werner. The French mineralogist Rene Just Hauy suggested it should be named Idocrase four years later. Werner’s name takes precedence. <br />
<br />
Variental Names: Cyprine, Californite<br />
<br />
Cyprine is a blue copper containing variety of vesuvianite that was first described from Norway about 1821 by the famous mineralogist Berzelius; the name is derived from Cyprium, the ancient term for copper. <br />
<br />
Californite is a compact massive form of vesuvianite that has an appearance to poor quality jade. It has historically be used as a jade simulant. It was first described by famed gemologist George Frederick Kunz in 1903, who suggested the name “californite” in honor of the state in which it was found. Dietrich (2005) offered the following opinion: “With all due regards to G.F. Kunz, I believe that… vesuvianite would have gained more "prestige" in gemology if the term californite had never been introduced.” He added “…the use of any gem material as a simulant serves only to denigrate its use under its own name.” Californite has also been called “American Jade”, “California Jade”, and “Vesuvianite Jade”. Any usage of names for vesuvianite which include “jade” should be discouraged. <br />
<br />
Crystal System: tetragonal or monoclinic<br />
<br />
Crystal Habit: prismatic to equant stubby crystals; massive granular to fine grained.<br />
<br />
Composition: Ca10Mg2Al4(SiO4)5(Si2O7)2(OH)4 often containing trace to minor amounts of iron, copper up to 2.1% as Cu in cyprine), chromium, manganese, titanium, boron or beryllium.<br />
<br />
Diagnostics:<br />
<br />
Peridot has a lower refractive index (1.654 to 1.670).The californite variety of vesuvianite floats or sinks slowly in methylene iodide; jadeite sinks (specific gravity less than 3.3). Nephrite has a lower specific gravity (3.295). <br />
<br />
Color: yellow, yellowish green, green, emerald green, yellow brown, brown, blue, violet to magneta; sometimes displays distinct color zoning.<br />
<br />
Magnification:<br />
<br />
Under magnification, the cyprine variety may exhibit a distinctly fibrous appearance.<br />
<br />
Optical and Physical Properties:<br />
<br />
Cleavage: poor on {110}, {100} and very poor on {001}<br />
<br />
Fracture: subconcoidal to uneven<br />
<br />
Specific Gravity: 3.32 - 3.34 (measured); 3.42 (calculated)<br />
<br />
Hardness: 6 to 7<br />
<br />
Lustre: Vitreous to resinous<br />
<br />
Optical Nature: Uniaxial (+) or Uniaxial (-); biaxial vesuvianite has been observed.<br />
<br />
Refractive Index: ω = 1.703 – 1.752 ε = 1.700 – 1.746. The variety cyprine from Franklin New Jersey demonstrates a lower range of refractive indices, with ω = 1.696 – 1.712 ε = 1.710 – 1.719. <br />
<br />
Birefringence: approximately 0.005<br />
<br />
Dispersion: strong<br />
<br />
Pleochroism: weak; O = colorless to yellowish, E = yellowish, greenish, brownish<br />
<br />
Spectroscope:<br />
<br />
Treatments: <br />
<br />
Phenomenon:<br />
<br />
Synthetics: none<br />
<br />
Imitations:<br />
<br />
Occurence:<br />
<br />
The Jeffrey Mine in Asbestos, Quebec has afforded facet rough that is predominantly yellow-green in color, similar to peridot; the mine has also produced an emerald green chrome-bearing vesuvianite and a violet to magenta manganoan vesuvianite that is sometimes called “manganovesuvianite” (this term is too close to the name of a different, non-gem mineral species, “manganvesuvianite” for comfort and should be discouraged). Bicolored facetted stones consisting of yellow-green common vesuvianite on one side, and pale magenta manganoan vesuvianite on the other, have been cut. Italy – most notably Bellecombe in Val d’Aosta has produced greenish brown to brown faceting rough. During the past decade, Fushan, Hebei Province, China has produced moderate quantities of deep yellow-brown (sometimes called “root beer”) colored crystals with gemmy areas capable of being facetted and cut en cabochon. Kaiiado District, Rift Valley Province, Kenya has produced greenish yellow to yellowish green vesuvianite faceting rough. <br />
<br />
Cyprine - The original find was of no interest as a gem material, but a significant quantity of cyprite was uncovered in 1922 during mining at Franklin, New Jersey, about 850 feet underground. Reports have been made of facetted specimens of cyprine from Sri Lanka, Jakobsberg Mine, Värmland, Sweden, and Pakistan; all are a pale blue tinged with grey. <br />
<br />
Californite - Northern California has produced Californite at several locations, including Happy Camp in Siskyou County, the Pulga Deposit on the North Fork of the Feather River, Butte County, and Tulare County.<br />
<br />
Sources:<br />
<br />
Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona<br />
<br />
Dietrich, R. V. (2005): “Vesuvianite” (webpage at: http://www.cst.cmich.edu/users/dietr1rv/vesuvianite.htm)<br />
<br />
Kunz, George Frederick (1903), American Journal of Science, 4th. Series, Vol. 16 pp397-398 “Californite (vesuvianite); a new ornamental stone”<br />
Palache, Charles, Harry Berman & Clifford Frondel (1944): The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition <br />
Shannon, E. V. (1922) Note on the cyprine from Franklin Furnace, New Jersey. American Mineralogist, 7, 140-142. <br />
<br />
External Links:</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Table_Of_Contents&diff=5333Table Of Contents2007-01-17T16:30:09Z<p>Russell: </p>
<hr />
<div>In this TOC (Table Of Contents) you will find pages that have been published presented in blue and pages that yet need to be written presented in red. For better navigation, we list the pages in 3 categories:<br />
#Theory - Basic and in-depth mechanisms involved in gemology<br />
#Practical - Descriptions of instruments, techniques and other practical discussions<br />
#Gemstones - Information about the gemstone at hand<br />
<br />
For the neophyte it is best to start in that order as some words and principles introduced in the theory pages will need to be understood first. At the very least, one should learn the theory in the "basic" sections of the pages.<br /><br />
Although gemology is not rocket science, some science and math is involved. We don't believe in the dumbing-down of gemology, so you should be ready and willing to expand your horizons. If you find any of the technical concepts difficult to visualize or grasp, go to the forum (the link is above) and ask. We will help you with it, and at the same time you will help this project become more complete for those who come after you. <br />
<br />
We never said it was going to be easy. But it's a heck of an interesting ride.<br />
<br />
<br />
{| {{toctable}} width="100%"<br />
<br />
!Theory <br />
!Practical<br />
!Gemstones<br />
<br />
|-<br />
<br />
|style="padding-right:5px" valign="top"|<br />
:'''Content'''<br />
#[[Introduction to Gemology]]<br />
##[[Introduction_to_Gemology#Education|Education]]<br />
##[[An Historical Look at our Obsession with Gems]]<br />
##[[Glossary of Terms]]<br />
#[[Origins of minerals]]<br />
##[[Origins_of_minerals#Igneous_.28Magmatic.29_rocks|Igneous rocks]]<br />
##[[Origins_of_minerals#Sedimentary_rocks|Sedimentary rocks]]<br />
##[[Origins_of_minerals#Metamorphic_rocks|Metamorphic rocks]]<br />
#[[The Chemistry of Gemstones]]<br />
##[[Isomorphous replacement]]<br />
##[[The Chemical Classification of Gems & Minerals]]<br />
#[[Crystallography]]<br />
##[[Crystal Systems]]<br />
##[[Form]]<br />
##[[Habit]]<br />
##[[Symmetry]]<br />
##[[Twinning]]<br />
#[[Cleavage]]<br />
#[[Cleavage#Parting|Parting]]<br />
#[[Cleavage#Fracture|Fracture]]<br />
#[[Optical properties of gemstones]]<br />
##[[Nature of light]]<br />
###[[Nature_of_light#The_electromagnetic_wave_theory |The electromagnetic wave theory]]<br />
###[[Nature_of_light#The_quantum_theory |The quantum theory]]<br />
###[[Nature_of_light#The_electromagnetic_spectrum |The electromagnetic spectrum]]<br />
##[[Reflection effects]]<br />
###[[Luster]]<br />
###[[Sheen]]<br />
####[[Sheen#Chatoyancy | Chatoyancy]]<br />
####[[Sheen#Asterism | Asterism]]<br />
####[[Sheen#Iridescence | Iridescence]]<br />
###[[Brilliance | Brilliance (Total Internal Reflection)]]<br />
##[[Polarization]]<br />
##[[Pleochroism]]<br />
##[[Color]]<br />
###[[Causes of color]]<br />
##[[Refraction]]<br />
###[[Double Refraction]]<br />
##[[Dispersion]]<br />
##[[Diffraction]]<br />
##[[Interference]]<br />
##[[Luminescence]]<br />
###[[Luminescence#Fluorescence | Fluorescence]]<br />
###[[Luminescence#Phosphorescence | Phosphorescence]]<br />
###[[Luminescence#Tenebrescence | Tenebrescence]]<br />
###[[Luminescence#Triboluminescence | Triboluminescence]]<br />
#[[Hardness]]<br />
#[[Specific Gravity]]<br />
#[[Math| Basic math for gemology]]<br />
##[[Math#Cross-multiplication | Cross-multiplication]]<br />
##[[Math#Sine.2C_cosine_and_tangent | Sine, cosine and tangent]]<br />
##[[Math#Degrees.2C_minutes_and_seconds | Degrees, minutes and seconds]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
#[[Equipment used to identify gemstones]]<br />
##[[10x Loupe]]<br />
##[[Spectroscope]]<br />
##[[Refractometer]]<br />
##[[Polariscope]]<br />
##[[Dichroscope]]<br />
##[[Immersion Cell]]<br />
##[[Color Filters]]<br />
##[[Microscope]]<br />
##[[Hydrostatic Balance]]<br />
##[[Heavy Liquids]]<br />
##[[Hardness#Hardness_pencils|Hardness pencils]]<br />
#[[Inclusions]]<br />
#[[Synthetic gemstones]]<br />
#[[Visual Optics]]<br />
##[[The Hodgkinson Method]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
*[[Alphabetic list by gemstone name]]<br />
#[[Diamond]]<br />
#[[Corundum]]<br />
##[[Ruby]]<br />
##[[Sapphire]]<br />
#[[Beryl]]<br />
##[[Aquamarine]]<br />
##[[Bixbite]]<br />
##[[Emerald]]<br />
###[[Vanadium Beryl]]<br />
##[[Goshenite]]<br />
##[[Green Beryl]]<br />
##[[Heliodor]]<br />
##[[Maxixe]]<br />
##[[Morganite]]<br />
##[[Riesling]]<br />
##[[True Blue]]<br />
##[[Pezzottaite]] (Beryl Group)<br />
#[[Quartz]]<br />
##[[Amethyst]]<br />
##[[Ametrine]]<br />
##[[Citrine]]<br />
##[[Prasiolite]]<br />
##[[Rock Crystal]]<br />
##[[Rose Quartz]]<br />
##[[Smokey Quartz]]<br />
#[[Quartz - Microcrystalline]]<br />
##[[Chalcedony]]<br />
###[[Agate]]<br />
###[[Bloodstone]]<br />
###[[Carnelian]]<br />
###[[Chrysoprase]]<br />
###[[Jasper]]<br />
###[[Onyx]]<br />
###[[Sard]]<br />
###[[Sardonyx]]<br />
###[[Tigereye]]<br />
#[[Zoisite]]<br />
##[[Tanzanite]]<br />
##[[Thulite]]<br />
#[[Garnet]]<br />
##[[Almandine]]<br />
##[[Andradite]]<br />
###[[Andradite#Demantoid|Demantoid]]<br />
##[[Grossular]]<br />
###[[Grossular#Chrome_grossular|Chrome grossular]]<br />
###[[Grossular#Hessonite|Hessonite]]<br />
###[[Grossular#Hydrogrossular |Hydrogrossular]]<br />
###[[Grossular#Mali|Mali]]<br />
###[[Grossular#Tsavorite|Tsavorite]]<br />
##[[Pyrope]]<br />
##[[Spessartite]]<br />
##[[Uvarovite]]<br />
#[[Diopside]]<br />
##[[Chrome Diopside]]<br />
##[[Tashmarine]]&trade;<br />
#[[Feldspar]]<br />
##[[Amazonite]]<br />
##[[Andesine]]<br />
##[[Labradorite]]<br />
##[[Moonstone]]<br />
##[[Spectrolite]]<br />
##[[Sunstone]]<br />
#[[Spodumene]]<br />
##[[Hiddenite]]<br />
##[[Kunzite]]<br />
#[[Chrysoberyl]]<br />
##[[Alexandrite]]<br />
#[[Spinel]]<br />
#[[Tourmaline]]<br />
##[[Achroite]]<br />
##[[Bi-color]]<br />
##[[Chrome]]<br />
##[[Dravite]]<br />
##[[Indicolite]]<br />
##[[Liddicoatite]]<br />
##[[Paraiba type]]<br />
##[[Rubellite]]<br />
##[[Schorl]]<br />
##[[Tri-Color]]<br />
##[[Verdite]]<br />
##[[Watermelon]]<br />
#[[Amber]]<br />
#[[Ammolite]]<br />
#[[Anatase]]<br />
#[[Andalusite]]<br />
#[[Apatite]]<br />
#[[Benitoite]]<br />
#[[Bowenite]]<br />
#[[Charoite]]<br />
#[[Chrysocolla]]<br />
#[[Coral]]<br />
#[[Danburite]]<br />
#[[Datolite]]<br />
#[[Dioptase]]<br />
#[[Enstatite]]<br />
#[[Fluorite]]<br />
#[[Glass]]<br />
##[[Goldstone]]<br />
#[[Hauyne]]<br />
#[[Iolite]]<br />
#[[Jade]]<br />
##[[Jadeite]]<br />
##[[Nephrite]]<br />
#[[Kornerupine]]<br />
#[[Lapis Lazuli]]<br />
#[[Larimar]]<br />
#[[Maw-sit-sit]]<br />
#[[Opal]]<br />
##[[Black Opal]]<br />
##[[Blue Peruvian Opal]]<br />
##[[Boulder Opal]]<br />
##[[Fire Opal]]<br />
#[[Pearl]]<br />
##[[Salt water]]<br />
###[[Akoya]]<br />
###[[Tahitian]]<br />
###[[South Sea]]<br />
###[[Mabé]]<br />
###[[Conch Pearl]]<br />
###[[Melo Pearl]]<br />
###[[Quahog]]<br />
##[[Freshwater Pearl]]<br />
###[[Kasumiga pearls]]<br />
###[[Chinese freshwater pearls]]<br />
#[[Peridot]]<br />
#[[Poudretteite]]<br />
#[[Scapolite]]<br />
#[[Sodalite]]<br />
##[[Hackmanite]]<br />
#[[Sphalerite]]<br />
#[[Sphene]]<br />
#[[Topaz]]<br />
#[[Turquoise]]<br />
#[[Vesuvianite]]<br />
#[[Willemite]]<br />
#[[Zincite]]<br />
#[[Zircon]]<br />
|}</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Danburite&diff=5325Danburite2007-01-17T03:44:52Z<p>Russell: </p>
<hr />
<div>{{danburite}}<br />
<br />
Danburite was named for the town of Danbury, Fairfield County, Conneticut, where it was first reported in 1839. This initial discovery was of no gemological interest, but by 1880, an additional occurrence in Russell, St Lawrence County, New York was producing facetable rough. Although danburite is now known from many localities around the world, only a few have produced material of sufficient clarity to be facetted.<br />
<br />
==Chemical composition==<br />
<br />
Calcium boron silicate, CaB2(SiO4)2 , sometimes with minor to trace amounts of iron, manganese, sodium, and magnesium.<br />
<br />
==Diagnostics==<br />
<br />
Danburite may be confused with [[topaz]], [[tourmaline]], [[andalusite]] and [[apatite]].<br />
<br />
===Color===<br />
<br />
Colorless to pale pink; golden yellow, yellow-brown.<br />
<br />
===Refractive index===<br />
<br />
Danburite is biaxial with either a negative or a positve optical sign, depending on the wavelength of the lightsource. For sodium light (n<sub>D</sub>) it will be negative. The use of blue light will give a positive optical sign.<br /><br />
Beta is halfway between alpha and gamma.<br />
<br />
Refractive index: n<sub>α</sub> =1.630, n<sub>β</sub> =1.633, n<sub>γ</sub> =1.636. <br /><br />
Birefringence: 0.006<br />
<br />
Topaz will have lower readings in RI but a higher birefringence.<br />
<br />
===Specific gravity===<br />
<br />
The SG range of danburite goes from 2.93 to 3.02 (mean = 3.0) and it will float in [[Heavy Liquids|heavy liquids]] 3.06 and 3.33 while andalusite will sink in 3.06 and topaz will sink in both.<br />
<br />
===Fluorescence===<br />
<br />
The majority of danburites fluoresce a blue-white color in longwave ultraviolet radiation. This must not, however, be considered wholly diagnostic.<br />
<br />
===Spectroscope===<br />
<br />
Danburite may show a rare earth spectrum due to didymium (lines in the yellow).<br />
<br />
==Treatments==<br />
<br />
Danburite may turn pink on irradiation.<br />
<br />
==Occurrence==<br />
<br />
Danburite occurs in pegmatites and in carbonate rocks that have been metamorphosed and exposed with hydrothermal activity.<br />
<br />
Large quantities of water-clear to pale-pink danburite have been obtained from Charcas, San Luis Potosí, Mexico since the late 1950's; Mogok, Mandalay Division, Myanmar (Burma), has produced rough exhibiting a very pleasing straw-yellow or golden color; and distinctly golden-brownish to straw yellow to amber-yellow rough has been obtained from the Anjanabonoina pegmatites and the Madagascar Sahatany Pegmatite Field and other sites in Antananarivo Province, Madagascar. Sherry to golden colored danburite rough has been produced from Dal'negorsk (Dalnegorsk), Primorskiy Kray, Russia.<br />
<br />
==Sources:==<br />
*Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona<br />
*Palache, Charles, Harry Berman & Clifford Frondel (1944): The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Datolite&diff=5324Datolite2007-01-17T03:43:31Z<p>Russell: /* Sources */</p>
<hr />
<div>{{datolite}}<br />
<br />
[[image:datolite1.jpg|left|200px|thumb|Datolite from the Caledonia Mine, Mass City, Michigan]]<br />
<br clear="left" /><br />
Datolite was named 1806 by Professor Jens Esmark from the Greek “to divide,” referring to the granular structure of the first specimens studied from Arendal, Norway.<br />
<br />
==Chemical composition==<br />
Calcium boron silicate hydroxide, CaBSiO4(OH) with minor to trace amounts of iron, manganese, and aluminum.<br />
<br />
==Diagnostics==<br />
<br />
===Color===<br />
<br />
Crystals are colorless to white, often with a pale green or greenish yellow tint. Massive datolite is translucent to opaque grayish, reddish, pink, brown or yellow.<br />
<br />
===Refractive index===<br />
<br />
Optical nature and sign: biaxial negative<br /><br />
Refractive Index: n<sub>α</sub> = 1.622 – 1.626 n<sub>β</sub> = 1.649 – 1.654 n<sub>γ</sub> = 1.666 – 1.670<br />
<br />
===Magnification===<br />
<br />
Massive datolite from Michigan cut en cabochon sometimes exhibits microscopic inclusions of native copper. The copper has sometimes oxidized to give the rough a copper-green color.<br />
<br />
==Occurence==<br />
<br />
Small quantities of greenish yellow to colorless datolite faceting rough have been produced at Dal'negorsk (Dalnegorsk), Primorskiy Kray, Russia. In addition to faceting rough, there was a largely unsuccessful attempt about 2002 to introduce a skarn rock composed of wollastonite and datolite to the US lapidary market; the material is marked by alternating bands light and dark olive-green bands and swirls. The skarn was apparently also produced in Primorskiy Kray (Dalnegorsk?). Compact, porcelain-like masses of datolite, some as large as 30cm in diameter and of a pleasing brown, red, yellow, malachite-green, white or grey color,, have been recovered since the mid-19th century from dozens of mines in Houghton, Keweenaw, and Ontonagen counties in Michigan’s famed “Copper Peninsula.” Rough is still being recovered by reworking abandoned mine dumps as well as scuba diving off the coastline.<br />
<br />
==Sources==<br />
<br />
<br />
*Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona<br />
<br />
*Palache, Charles, Harry Berman & Clifford Frondel (1944): The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition<br />
<br />
*Rosemeyer, T. (2003) The occurrence of porcelaneous datolite in michigan's lake superior copper district Part I: Northern Keweenaw County and Isle Royale National Park Rocks & Minerals, Vol. 78 No. 3 pp. 170-88<br />
<br />
*Rosemeyer, T. (2005) The occurrence of porcelaneous datolite in Michigan's Lake Superior Copper District: part 2: Southern Keweenaw, Houghton, and Ontonagon Counties, Michigan. Rocks & Minerals, Rocks & Minerals Vol 80 No. 3 pp154-177<br />
<br />
==External links==<br />
* [http://www.minsocam.org/MSA/collectors_corner/vft/mi4c.htm Keneewa Michigan field trip]<br />
* [http://www.minsocam.org/MSA/collectors_corner/vft/mi4c1.htm Lapidary additional]</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Willemite&diff=5323Willemite2007-01-17T03:37:49Z<p>Russell: </p>
<hr />
<div>Willemite <br />
<br />
Crystal System: Hexagonal (trigonal)<br />
<br />
Crystal Habit: crystals are long to short prismatic, to 10cm in length. Also fine to coarse granular massive.<br />
<br />
Composition: Zinc silicate, Zn2Si04 . Minor to trace amounts of iron, aluminum, manganese, calcium and magnesium may be present.<br />
<br />
Diagnostics:<br />
<br />
Yellow to yellow-green shades of willemite can be confused with golden beryl (which possesses a lower refractive index at 1.570 - 1.575, is harder at 7.5 to 8, and has a lower specific gravity of 2.72), and chrysoberyl (which is harder at 8.5, has a higher specific gravity 3.73, and a higher refractive index at 1.746 – 1.755)<br />
<br />
Color: Transparent rough is colorless to golden yellow, pale blue-green. A canary-yellow variety of willemite from Tsumeb, Namibia has been documented, with the color attributed to cadmium (although whether the cadmium is present at a substitute for an essential component, or as finely divided greenockite – cadmium sulfide – is uncertain). Massive material cut en cabochon may be white, apple green, amethystine, yellow to golden brown, grayish, brown. An opaque flesh-red variety is called “troostite” which consists of exsolution laminae of willemite in tephroite, a manganese silicate. <br />
<br />
Magnification: may exhibit black inclusions of franklinite, an iron manganese zinc oxide.<br />
<br />
Optical and Physical Properties:<br />
<br />
Cleavage: indistinct<br />
<br />
Fracture: conchoidal to irregular<br />
<br />
Specific Gravity: 3.89 – 4.19<br />
<br />
Hardness: 5.5<br />
<br />
Lustre: Vitreous to resinous<br />
<br />
Optical Nature: Uniaxial (+)<br />
<br />
Refractive Index: ω = 1.691 – 1.694 , ε = 1.719 – 1.725<br />
<br />
Birefringence: <br />
<br />
Dispersion: <br />
<br />
Pleochroism:<br />
<br />
Spectroscope:<br />
<br />
Treatments: there are reports that some rough has been heat treated to convert it from colorless to blue. <br />
<br />
Phenomenon: <br />
<br />
The willemite from Franklin and Ogdensburg, Sussex County, New Jersey commonly fluoresces a brilliant green under shortwave ultraviolet. It also commonly is phosphorescent, with some specimens continuing to luminesce for hours after excitation has terminated; triboluminscence (luminescence when the specimen is abraded or broken) has been observed. Willemite with a butter-yellow fluorescence has been observed but is uncommon. Fluorescent response in Namibian willemite appears to be more erratic. Fluorescence must not be considered diagnostic; non-fluorescent willemite has been observed. The “troostite” variety may appear as homogenous willemite in white light, but can exhibit thin lines or streaks of fluorescent green in a non-fluorescent groundmass.<br />
<br />
Synthetics:<br />
<br />
Imitations:<br />
<br />
Occurence:<br />
<br />
Willemite occurs as a primary and secondary mineral in metamorphosed zinc ore deposits. It is uncommon, except at the zinc mines of Franklin and Ogdensburg in Sussex County, New Jersey, where it is one of the three primary ore minerals. Enormous tonnages were mined between circa 1830 and circa 1980. In the late 19th century, one crystal recovered yielded enough rough to cut several stones; the largest faceted stone was 8 carats and became part of the Frederick A. Canfield collection. Facet-grade willemite has also been recovered from the Tsumeb (Tsumcorp) Mine in Tsumeb, Namibia.<br />
<br />
Of willemite as a gemstone, Dunn (1995) writes: “Willemite has been cut as an uncommon, exotic gem. Fine-quality gemstones have been cut from orange-yellow willemite crystals: gems of 11.1 and 11.7 carats are in the Smithsonian Institution; one of 36.93 carats is in the Harvard Mineralogical Museum; and one of 6.28 carats is in the American Museum of Natural History in New York. Massive material may be quite clean internally and translucent and has provided some gemmy material for the cutting of chabochons.” <br />
<br />
Care and Maintenance: <br />
<br />
Willemite can be decomposed by mineral acids into a colorless silica gel; care should be exercised in the use of chemical cleaning agents.<br />
<br />
Sources:<br />
<br />
Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona<br />
<br />
Dunn, Pete J. (1995) Franklin and Sterling Hill, New Jersey: the world’s most magnificent mineral deposits <br />
<br />
Palache, C. (1935), Minerals of Franklin and Sterling Hill, New Jersey, USG Professional Paper 180<br />
<br />
Palache, Charles, Harry Berman & Clifford Frondel (1944): The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition<br />
<br />
External Links:</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Table_Of_Contents&diff=5322Table Of Contents2007-01-17T03:32:42Z<p>Russell: </p>
<hr />
<div>In this TOC (Table Of Contents) you will find pages that have been published presented in blue and pages that yet need to be written presented in red. For better navigation, we list the pages in 3 categories:<br />
#Theory - Basic and in-depth mechanisms involved in gemology<br />
#Practical - Descriptions of instruments, techniques and other practical discussions<br />
#Gemstones - Information about the gemstone at hand<br />
<br />
For the neophyte it is best to start in that order as some words and principles introduced in the theory pages will need to be understood first. At the very least, one should learn the theory in the "basic" sections of the pages.<br /><br />
Although gemology is not rocket science, some science and math is involved. We don't believe in the dumbing-down of gemology, so you should be ready and willing to expand your horizons. If you find any of the technical concepts difficult to visualize or grasp, go to the forum (the link is above) and ask. We will help you with it, and at the same time you will help this project become more complete for those who come after you. <br />
<br />
We never said it was going to be easy. But it's a heck of an interesting ride.<br />
<br />
<br />
{| {{toctable}} width="100%"<br />
<br />
!Theory <br />
!Practical<br />
!Gemstones<br />
<br />
|-<br />
<br />
|style="padding-right:5px" valign="top"|<br />
:'''Content'''<br />
#[[Introduction to Gemology]]<br />
##[[Introduction_to_Gemology#Education|Education]]<br />
##[[An Historical Look at our Obsession with Gems]]<br />
##[[Glossary of Terms]]<br />
#[[Origins of minerals]]<br />
##[[Origins_of_minerals#Igneous_.28Magmatic.29_rocks|Igneous rocks]]<br />
##[[Origins_of_minerals#Sedimentary_rocks|Sedimentary rocks]]<br />
##[[Origins_of_minerals#Metamorphic_rocks|Metamorphic rocks]]<br />
#[[The Chemistry of Gemstones]]<br />
##[[Isomorphous replacement]]<br />
##[[The Chemical Classification of Gems & Minerals]]<br />
#[[Crystallography]]<br />
##[[Crystal Systems]]<br />
##[[Form]]<br />
##[[Habit]]<br />
##[[Symmetry]]<br />
##[[Twinning]]<br />
#[[Cleavage]]<br />
#[[Cleavage#Parting|Parting]]<br />
#[[Cleavage#Fracture|Fracture]]<br />
#[[Optical properties of gemstones]]<br />
##[[Nature of light]]<br />
###[[Nature_of_light#The_electromagnetic_wave_theory |The electromagnetic wave theory]]<br />
###[[Nature_of_light#The_quantum_theory |The quantum theory]]<br />
###[[Nature_of_light#The_electromagnetic_spectrum |The electromagnetic spectrum]]<br />
##[[Reflection effects]]<br />
###[[Luster]]<br />
###[[Sheen]]<br />
####[[Sheen#Chatoyancy | Chatoyancy]]<br />
####[[Sheen#Asterism | Asterism]]<br />
####[[Sheen#Iridescence | Iridescence]]<br />
###[[Brilliance | Brilliance (Total Internal Reflection)]]<br />
##[[Polarization]]<br />
##[[Pleochroism]]<br />
##[[Color]]<br />
###[[Causes of color]]<br />
##[[Refraction]]<br />
###[[Double Refraction]]<br />
##[[Dispersion]]<br />
##[[Diffraction]]<br />
##[[Interference]]<br />
##[[Luminescence]]<br />
###[[Luminescence#Fluorescence | Fluorescence]]<br />
###[[Luminescence#Phosphorescence | Phosphorescence]]<br />
###[[Luminescence#Tenebrescence | Tenebrescence]]<br />
###[[Luminescence#Triboluminescence | Triboluminescence]]<br />
#[[Hardness]]<br />
#[[Specific Gravity]]<br />
#[[Math| Basic math for gemology]]<br />
##[[Math#Cross-multiplication | Cross-multiplication]]<br />
##[[Math#Sine.2C_cosine_and_tangent | Sine, cosine and tangent]]<br />
##[[Math#Degrees.2C_minutes_and_seconds | Degrees, minutes and seconds]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
#[[Equipment used to identify gemstones]]<br />
##[[10x Loupe]]<br />
##[[Spectroscope]]<br />
##[[Refractometer]]<br />
##[[Polariscope]]<br />
##[[Dichroscope]]<br />
##[[Immersion Cell]]<br />
##[[Color Filters]]<br />
##[[Microscope]]<br />
##[[Hydrostatic Balance]]<br />
##[[Heavy Liquids]]<br />
##[[Hardness#Hardness_pencils|Hardness pencils]]<br />
#[[Inclusions]]<br />
#[[Synthetic gemstones]]<br />
#[[Visual Optics]]<br />
##[[The Hodgkinson Method]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
*[[Alphabetic list by gemstone name]]<br />
#[[Diamond]]<br />
#[[Corundum]]<br />
##[[Ruby]]<br />
##[[Sapphire]]<br />
#[[Beryl]]<br />
##[[Aquamarine]]<br />
##[[Bixbite]]<br />
##[[Emerald]]<br />
###[[Vanadium Beryl]]<br />
##[[Goshenite]]<br />
##[[Green Beryl]]<br />
##[[Heliodor]]<br />
##[[Maxixe]]<br />
##[[Morganite]]<br />
##[[Riesling]]<br />
##[[True Blue]]<br />
##[[Pezzottaite]] (Beryl Group)<br />
#[[Quartz]]<br />
##[[Amethyst]]<br />
##[[Ametrine]]<br />
##[[Citrine]]<br />
##[[Prasiolite]]<br />
##[[Rock Crystal]]<br />
##[[Rose Quartz]]<br />
##[[Smokey Quartz]]<br />
#[[Quartz - Microcrystalline]]<br />
##[[Chalcedony]]<br />
###[[Agate]]<br />
###[[Bloodstone]]<br />
###[[Carnelian]]<br />
###[[Chrysoprase]]<br />
###[[Jasper]]<br />
###[[Onyx]]<br />
###[[Sard]]<br />
###[[Sardonyx]]<br />
###[[Tigereye]]<br />
#[[Zoisite]]<br />
##[[Tanzanite]]<br />
##[[Thulite]]<br />
#[[Garnet]]<br />
##[[Almandine]]<br />
##[[Andradite]]<br />
###[[Andradite#Demantoid|Demantoid]]<br />
##[[Grossular]]<br />
###[[Grossular#Chrome_grossular|Chrome grossular]]<br />
###[[Grossular#Hessonite|Hessonite]]<br />
###[[Grossular#Hydrogrossular |Hydrogrossular]]<br />
###[[Grossular#Mali|Mali]]<br />
###[[Grossular#Tsavorite|Tsavorite]]<br />
##[[Pyrope]]<br />
##[[Spessartite]]<br />
##[[Uvarovite]]<br />
#[[Diopside]]<br />
##[[Chrome Diopside]]<br />
##[[Tashmarine]]&trade;<br />
#[[Feldspar]]<br />
##[[Amazonite]]<br />
##[[Andesine]]<br />
##[[Labradorite]]<br />
##[[Moonstone]]<br />
##[[Spectrolite]]<br />
##[[Sunstone]]<br />
#[[Spodumene]]<br />
##[[Hiddenite]]<br />
##[[Kunzite]]<br />
#[[Chrysoberyl]]<br />
##[[Alexandrite]]<br />
#[[Spinel]]<br />
#[[Tourmaline]]<br />
##[[Achroite]]<br />
##[[Bi-color]]<br />
##[[Chrome]]<br />
##[[Dravite]]<br />
##[[Indicolite]]<br />
##[[Liddicoatite]]<br />
##[[Paraiba type]]<br />
##[[Rubellite]]<br />
##[[Schorl]]<br />
##[[Tri-Color]]<br />
##[[Verdite]]<br />
##[[Watermelon]]<br />
#[[Amber]]<br />
#[[Ammolite]]<br />
#[[Anatase]]<br />
#[[Andalusite]]<br />
#[[Apatite]]<br />
#[[Benitoite]]<br />
#[[Bowenite]]<br />
#[[Charoite]]<br />
#[[Chrysocolla]]<br />
#[[Coral]]<br />
#[[Danburite]]<br />
#[[Datolite]]<br />
#[[Dioptase]]<br />
#[[Enstatite]]<br />
#[[Fluorite]]<br />
#[[Glass]]<br />
##[[Goldstone]]<br />
#[[Hauyne]]<br />
#[[Iolite]]<br />
#[[Jade]]<br />
##[[Jadeite]]<br />
##[[Nephrite]]<br />
#[[Konerupine]]<br />
#[[Lapis Lazuli]]<br />
#[[Larimar]]<br />
#[[Maw-sit-sit]]<br />
#[[Opal]]<br />
##[[Black Opal]]<br />
##[[Blue Peruvian Opal]]<br />
##[[Boulder Opal]]<br />
##[[Fire Opal]]<br />
#[[Pearl]]<br />
##[[Salt water]]<br />
###[[Akoya]]<br />
###[[Tahitian]]<br />
###[[South Sea]]<br />
###[[Mabé]]<br />
###[[Conch Pearl]]<br />
###[[Melo Pearl]]<br />
###[[Quahog]]<br />
##[[Freshwater Pearl]]<br />
###[[Kasumiga pearls]]<br />
###[[Chinese freshwater pearls]]<br />
#[[Peridot]]<br />
#[[Poudretteite]]<br />
#[[Scapolite]]<br />
#[[Sodalite]]<br />
##[[Hackmanite]]<br />
#[[Sphalerite]]<br />
#[[Sphene]]<br />
#[[Topaz]]<br />
#[[Turquoise]]<br />
#[[Vesuvianite]]<br />
#[[Willemite]]<br />
#[[Zincite]]<br />
#[[Zircon]]<br />
|}</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Zincite&diff=5321Zincite2007-01-17T02:52:11Z<p>Russell: /* Occurence */</p>
<hr />
<div>{{zincite}}<br />
<br />
==Habit==<br />
Pyramidal crystals, distinctly hemimorphic; massive<br />
<br />
==Chemical composition==<br />
Zinc oxide, ZnO. Usually with minor amounts of manganese (less than 7%), and minor to trace amounts of iron, magnesium and aluminum.<br />
<br />
==Diagnostics==<br />
Because of its high specific gravity, zincite is unlikely to be confused with any other gem material.<br />
<br />
===Color===<br />
Deep red, deep orange. Manganese is the coloring agent. Green zincite has been observed in nature but to date has not been found in sizes sufficient to facet.<br />
<br />
===Magnification===<br />
Black submetallic inclusions of franklinite or hetaerolite (both oxides containing zinc and manganese) are common.<br />
<br />
===Specific Gravity===<br />
5.66 (measured) 5.67 (calculated)<br />
<br />
===Refractive Index===<br />
n<sub>ε</sub> = 2.029, n<sub>ω</sub> = 2.013<br />
<br />
==Treatments==<br />
None known<br />
<br />
==Phenomenon==<br />
Zincite may, in extremely rarely instances, display a pale yellow fluorescence in long wave ultraviolet light. This has not yet been documented in cut stones.<br />
<br />
==Synthetics==<br />
Synthetic zincite flooded the US market in the late 1980’s and 1990’s, available in a rainbow of colors from pale green to green, pale red to deep red, and yellow to deep orange synthetic. This material was derived from the smokestacks of a metal refinery in Silesia, Poland, where it had crystallized over many years from volatized zinc oxide. Zincite is also grown in laboratories by several techniques, including hydrothermal, Czochralski pull, and vapor deposition (sublimation) methods.<br />
<br />
==Imitations==<br />
None reported.<br />
<br />
==Occurence== <br />
As a primary and secondary mineral in metamorphosed zinc-iron-manganese ore deposits. Zincite is actually very rare, except <br />
at the zinc mines of Franklin and Ogdensburg in Sussex County, New Jersey, where it is one of the three primary ore minerals. Enormous tonnages were mined between circa 1830 and circa 1980.<br />
<br />
==Sources==<br />
* Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona<br />
* Dunn, Pete J. (1995) Franklin and Sterling Hill, New Jersey: the world’s most magnificent mineral deposits<br />
* Palache, C. (1935), Minerals of Franklin and Sterling Hill, New Jersey, USG Professional Paper 180<br />
* Palache, Charles, Harry Berman & Clifford Frondel (1944), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Seventh edition</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Danburite&diff=5300Danburite2007-01-16T20:39:34Z<p>Russell: /* Refractive index */</p>
<hr />
<div>{{danburite}}<br />
<br />
Danburite was named for the town of Danbury, Fairfield County, Conneticut, where it was first reported in 1839. This initial discovery was of no gemological interest, but by 1880, an additional occurrence in Russell, St Lawrence County, New York was producing facetable rough. Although danburite is now known from many localities around the world, only a few have produced material of sufficient clarity to be facetted.<br />
<br />
==Chemical composition==<br />
<br />
Calcium boron silicate, CaB2(SiO4)2 , sometimes with minor to trace amounts of iron, manganese, sodium, and magnesium.<br />
<br />
==Diagnostics==<br />
<br />
Danburite may be confused with [[topaz]], [[tourmaline]], [[andalusite]] and [[apatite]].<br />
<br />
===Color===<br />
<br />
Colorless to pale pink; golden yellow, yellow-brown.<br />
<br />
===Refractive index===<br />
<br />
Danburite is biaxial with either a negative or a positve optical sign, depending on the wavelength of the lightsource. For sodium light (n<sub>D</sub>) it will be negative. The use of blue light will give a positive optical sign.<br /><br />
Beta is halfway between alpha and gamma.<br />
<br />
Refractive index: n<sub>α</sub> =1.630, n<sub>β</sub> =1.633, n<sub>γ</sub> =1.636. <br /><br />
Birefringence: 0.006<br />
<br />
Topaz will have lower readings in RI but a higher birefringence.<br />
<br />
===Specific gravity===<br />
<br />
The SG range of danburite goes from 2.93 to 3.02 (mean = 3.0) and it will float in [[Heavy Liquids|heavy liquids]] 3.06 and 3.33 while andalusite will sink in 3.06 and topaz will sink in both.<br />
<br />
===Fluorescence===<br />
<br />
The majority of danburites fluoresce a blue-white color in longwave ultraviolet radiation. This must not, however, be considered wholly diagnostic.<br />
<br />
===Spectroscope===<br />
<br />
Danburite may show a rare earth spectrum due to didymium (lines in the yellow).<br />
<br />
==Treatments==<br />
<br />
Danburite may turn pink on irradiation.<br />
<br />
==Occurence==<br />
<br />
Danburite occurs in pegmatites and in carbonate rocks that have been metamorphosed and exposed with hydrothermal activity.<br />
<br />
Large quantities of water-clear to pale-pink danburite have been obtained from Charcas, San Luis Potosí, Mexico since the late 1950's; Mogok, Mandalay Division, Myanmar (Burma), has produced rough exhibiting a very pleasing straw-yellow or golden color; and distinctly golden-brownish to straw yellow to amber-yellow rough has been obtained from the Anjanabonoina pegmatites and the Madagascar Sahatany Pegmatite Field and other sites in Antananarivo Province, Madagascar. Sherry to golden colored danburite rough has been produced from Dal'negorsk (Dalnegorsk), Primorskiy Kray, Russia.</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Hiddenite&diff=5251Hiddenite2007-01-15T19:28:06Z<p>Russell: </p>
<hr />
<div>{{hiddenite}}<br />
<br />
[[image:hidd-afghan.jpg|framed|left|Faceted Yellow Hiddenite<br />
Photo courtesy of Wild Fish Gems]]<br />
<br clear="left" /><br />
Hiddenite is the yellow to green variety of [[spodumene]].<br /><br />
It was originally discovered in Hiddenite, North Carolina.<br />
<br />
==On The First Discovery And Early Mining of Hiddenite in North Carolina==<br />
<br />
The first specimens of the hiddenite variety of spodumene were recovered about 1879 in the tiny settlement of White Plains, west of Stony Point, Alexander County, North Carolina. According to contemporary accounts, a young man named Lackey brought them to the attention of J.A.D. Stephenson, a local merchant who was also an ardent collector of mineral and archaeological specimens (Anonymous, 1885). Stephenson had posted a reward for any and all interesting specimens brought in by local farmers, amoung which were included “green bolts” (the emeralds for which the region would later become renowned) and yellowish green transparent crystals which were found loose in the soil with the emeralds. Initially, the yellowish to greenish-yellow hiddenites were thought to be gemmy diopside, and Stephenson sent the specimens to Norman Spang of Pittsburg, PA, a prominent US mineral collector of the era. Soon afterwards, Stephenson brought the discovery to the attention of William Earl Hidden, who had been commissioned by Thomas Edison to search for any sources of platinum in North Carolina (an effort that was, in and of itself, stunningly unsuccessful). Hidden sent samples of the odd green material to John Lawrence Smith, a prominent chemist and mineralogist of Louisville, Kentucky. Smith correctly identified the specimens as being spodumene, and named them “hiddenite” in honor of Hidden. Smith's analysis of hiddenite did not note the presence of chromium; two years later, Friedrich A. Genth, Pennyslvania's State Mineralogist, published an analysis of hiddenite which detected chromium as 0.18% chromium oxide (Genth, 1883). During the hey-day of hiddenite mining in the 1880’s and 1890’s it was also known as “lithia emerald”. <br />
<br />
Hidden recognized the value of the emeralds and the potential of the new gemmy green spodumene. He acquired a tract of poor quality land from J Washington Warren, which was either the site of the initial discovery or near to it, for $1500 (the sale price was approximately three times the value of the land). The Emerald and Hiddenite Mining Company was organized and excavations on the site quickly recovered loose hiddenites and emeralds in the red, gravelly clay. At a depth of about 26 feet they struck bedrock and soon were uncovering hiddenites from solid rock. Oddly, period newspaper accounts and statements by Kunz (1892) indicate that mining on the site was never undertaken as a full time operation, but was only prosecuted a few weeks or months during the summer. Writing in 1892, Kunz described the hiddenite being recovered as “always transparent, ranges from colorless (rare) to a light yellow, into a yellowish green, then into a deep yellow emerald green. Sometimes an entire crystal has a uniform green color, but generally one end is yellow and the other green.” He added “The yellow color exhibited by the mineral in even the darkest green gems will prevent it from competing with the emerald, since it is this very quality that has kept down the prices of the Siberian demantoids or Uralian emeralds as the green garnets are variously termed. Dr. J Lawrence Smith says that the crystals, when cut and polished, resemble the emerald in luster, though the color is not so intense as in the finer variety of the latter gem. Prof. Edward S Dana says that, owing to its dichroism, it has a peculiar brilliancy which is wanting in the true emerald.” Kunz noted that the finest crystal recovered prior to 1892 measured 68 mm tall, and could have cut a gem of 5.5ct estimated weight. The size of most cut gems were small, with a 2ct hiddenite in the Augustus C. Hamlin collection being considered amoung the finest of the large stones. Between 1880 and 1888 approximately $7,500 worth of hiddenite was produced, with values ranging from $40 to $100 a carat (1892 US dollars). <br />
<br />
==Sources==<br />
<br />
*Anonymous (1885): ''Taylorsville And Aleck, Their Resources and Advantages, Their Enterprise and Progress'', The Landmark (newspaper), 8 May 1885<br />
*Davidson, S. C. (1927) American Mineralogist Vol. 27, pp 305-307 ''The Hiddenite Occurrence in North Carolina''<br />
*Genth, F. A. (1883) American Journal of Science Vol. 23 series 3, p68 ''Hiddenite"<br />
*Kunz, George Fredreick (1892) ''Gems and Precious Stones of North America''. The Scientific Publishing Company, New York NY ISBN 0486218554<br />
*Palache, C., Davidson, S. C., and Goranson, E.A. (1930) American Mineralogist Vol 15 No. 8 p. 280 ''The Hiddenite deposit in Alexander County, N.Carolina''<br />
*Smith, J. L. (1881) American Journal of Science Vol. 21 ser 3 pp128-30 (1881) ''Hiddenite, an emerald-green variety of spodumene''<br />
* ''Gemmology'' 3rd edition (2005) - Peter G. Read ISBN 0750664495</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Hiddenite&diff=5244Hiddenite2007-01-15T18:23:05Z<p>Russell: </p>
<hr />
<div>{{hiddenite}}<br />
<br />
Hiddenite is the green variety of spodumene.<br><br />
It was originally discovered in Hiddenite, North Carolina.<br />
<br />
<br />
<br />
== '''On The First Discovery And Early Mining of Hiddenite in North Carolina:''' ==<br />
<br />
The first specimens of the hiddenite variety of spodumene were recovered about 1879 in the tiny settlement of White Plains, west of Stony Point, Alexander County, North Carolina. According to contemporary accounts, a young man named Lackey brought them to the attention of J.A.D. Stephenson, a local merchant who was also an ardent collector of mineral and archaeological specimens (Anonymous, 1885). Stephenson had posted a reward for any and all interesting specimens brought in by local farmers, amoung which were included “green bolts” (the emeralds for which the region would later become renowned) and yellowish green transparent crystals which were found loose in the soil with the emeralds. Initially, the yellowish to greenish-yellow hiddenites were thought to be gemmy diopside, and Stephenson sent the specimens to Norman Spang of Pittsburg, PA, a prominent US mineral collector of the era. Soon afterwards, Stephenson brought the discovery to the attention of William Earl Hidden, who had been commissioned by Thomas Edison to search for any sources of platinum in North Carolina (an effort that was, in and of itself, stunningly unsuccessful). Hidden sent samples of the odd green material to John Lawrence Smith, a prominent chemist and mineralogist of Louisville, Kentucky. Smith correctly identified the specimens as being spodumene, and named them “hiddenite” in honor of Hidden. During the hey-day of hiddenite mining in the 1880’s and 1890’s it was also known as “lithia emerald”. <br />
<br />
Hidden recognized the value of the emeralds and the potential of the new gemmy green spodumene. He acquired a tract of poor quality land from J Washington Warren, which was either the site of the initial discovery or near to it, for $1500 (the sale price was approximately three times the value of the land). The Emerald and Hiddenite Mining Company was organized and excavations on the site quickly recovered loose hiddenites and emeralds in the red, gravelly clay. At a depth of about 26 feet they struck bedrock and soon were uncovering hiddenites from solid rock. Oddly, period newspaper accounts and statements by Kunz (1892) indicate that mining on the site was never undertaken as a full time operation, but was only prosecuted a few weeks or months during the summer. Writing in 1892, Kunz described the hiddenite being recovered as “always transparent, ranges from colorless (rare) to a light yellow, into a yellowish green, then into a deep yellow emerald green. Sometimes an entire crystal has a uniform green color, but generally one end is yellow and the other green.” He added “The yellow color exhibited by the mineral in even the darkest green gems will prevent it from competing with the emerald, since it is this very quality that has kept down the prices of the Siberian demantoids or Uralian emeralds as the green garnets are variously termed. Dr. J Lawrence Smith says that the crystals, when cut and polished, resemble the emerald in luster, though the color is not so intense as in the finer variety of the latter gem. Prof. Edward S Dana says that, owing to its dichroism, it has a peculiar brilliancy which is wanting in the true emerald.” Kunz noted that the finest crystal recovered prior to 1892 measured 68 mm tall, and could have cut a gem of 5.5ct estimated weight. The size of most cut gems were small, with a 2ct hiddenite in the Augustus C. Hamlin collection being considered amoung the finest of the large stones. Between 1880 and 1888 approximately $7,500 worth of hiddenite was produced, with values ranging from $40 to $100 a carat (1892 US dollars). <br />
<br />
'''References:'''<br />
<br />
Anonymous (1885): “Taylorsville And Aleck, Their Resources and Advantages, Their Enterprise and Progress” <br />
The Landmark (newspaper), 8 May 1885<br />
<br />
Davidson, S. C. (1927) American Mineralogist Vol. 27, pp 305-307 “The Hiddenite Occurrence in North Carolina”<br />
<br />
Kunz, George Fredreick (1892) Gems and Precious Stones of North America. The Scientific Publishing Company, New York NY<br />
<br />
Palache, C., Davidson, S. C., and Goranson, E.A. (1930) American Mineralogist Vol 15 No. 8 p. 280 "The Hiddenite deposit in Alexander County, N.Carolina"<br />
<br />
Smith, J. L. (1881) American Journal of Science Vol. 21 ser 3 pp128-30 (1881)"Hiddenite, an emerald-green variety of spodumene"</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Hiddenite&diff=5243Hiddenite2007-01-15T18:19:33Z<p>Russell: </p>
<hr />
<div>{{hiddenite}}<br />
<br />
Hiddenite is the green variety of spodumene.<br><br />
It was originally discovered in Hiddenite, North Carolina.<br />
<br />
<br />
<br />
== '''On The First Discovery And Early Mining of Hiddenite in North Carolina:''' ==<br />
<br />
The first specimens of the hiddenite variety of spodumene were recovered about 1879 in the tiny settlement of White Plains, west of Stony Point, Alexander County, North Carolina. According to contemporary accounts, a young man named Lackey brought them to the attention of J.A.D. Stephenson, a local merchant who was also an ardent collector of mineral and archaeological specimens (Anonymous, 1885). Stephenson had posted a reward for any and all interesting specimens brought in by local farmers, amoung which were included “green bolts” (the emeralds for which the region would later become renowned) and yellowish green transparent crystals which were found loose in the soil with the emeralds. Initially, the yellowish to greenish-yellow hiddenites were thought to be gemmy diopside, and Stephenson sent the specimens to Norman Spang of Pittsburg, PA, a prominent US mineral collector of the era. Soon afterwards, Stephenson brought the discovery to the attention of William Earl Hidden, who had been commissioned by Thomas Edison to search for any sources of platinum in North Carolina (an effort that was, in and of itself, stunningly unsuccessful). Hidden sent samples of the odd green material to John Lawrence Smith, a prominent chemist and mineralogist of Louisville, Kentucky. Smith correctly identified the specimens as being spodumene, and named them “hiddenite” in honor of Hidden. During the hey-day of hiddenite mining in the 1880’s and 1890’s it was also known as “lithia emerald”. <br />
<br />
Hidden recognized the value of the emeralds and the potential of the new gemmy green spodumene. He acquired a tract of poor quality land from J Washington Warren, which was either the site of the initial discovery or near to it, for $1500 (the sale price was approximately three times the value of the land). The Emerald and Hiddenite Mining Company was organized and excavations on the site quickly recovered loose hiddenites and emeralds in the red, gravelly clay. At a depth of about 26 feet they struck bedrock and soon were uncovering hiddenites from solid rock. Oddly, period newspaper accounts and statements by Kunz (1892) indicate that mining on the site was never undertaken as a full time operation, but was only prosecuted a few weeks or months during the summer. Writing in 1892, Kunz described the hiddenite being recovered as “always transparent, ranges from colorless (rare) to a light yellow, into a yellowish green, then into a deep yellow emerald green. Sometimes an entire crystal has a uniform green color, but generally one end is yellow and the other green.” He added “The yellow color exhibited by the mineral in even the darkest green gems will prevent it from competing with the emerald, since it is this very quality that has kept down the prices of the Siberian demantoids or Uralian emeralds as the green garnets are variously termed. Dr. J Lawrence Smith says that the crystals, when cut and polished, resemble the emerald in luster, though the color is not so intense as in the finer variety of the latter gem. Prof. Edward S Dana says that, owing to its dichroism, it has a peculiar brilliancy which is wanting in the true emerald.” Kunz noted that the finest crystal recovered prior to 1892 measured 68 mm tall, and could have cut a gem of 5.5ct estimated weight. The size of most cut gems were small, with a 2ct hiddenite in the Augustus C. Hamlin collection being considered amoung the finest of the large stones. Between 1880 and 1888 approximately $7,500 worth of hiddenite was produced, with values ranging from $40 to $100 a carat (1892 US dollars). <br />
<br />
References:<br />
<br />
Anonymous (1885): “Taylorsville And Aleck, Their Resources and Advantages, Their Enterprise and Progress” <br />
The Landmark (newspaper), 8 May 1885<br />
<br />
Davidson, S. C. (1927) American Mineralogist Vol. 27, pp 305-307 “The Hiddenite Occurrence in North Carolina”<br />
<br />
J.L.Smith (1881) American Journal of Science Vol. 21 ser 3 pp128-30 (1881)"Hiddenite, an emerald-green variety of spodumene" <br />
<br />
Palache, C., Davidson, S. C., and Goranson, E.A. (1930) American Mineralogist Vol 15 No. 8 p. 280 The Hiddenite deposit in Alexander County, N.Carolina"</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Hiddenite&diff=5241Hiddenite2007-01-15T18:17:01Z<p>Russell: </p>
<hr />
<div>{{hiddenite}}<br />
<br />
Hiddenite is the green variety of spodumene.<br><br />
It was originally discovered in Hiddenite, North Carolina.<br />
<br />
<br />
<br />
== '''On The First Discovery And Early Mining of Hiddenite in North Carolina:''' ==<br />
<br />
The first specimens of the hiddenite variety of spodumene were recovered about 1879 in the tiny settlement of White Plains, west of Stony Point, Alexander County, North Carolina. According to contemporary accounts, a young man named Lackey brought them to the attention of J.A.D. Stephenson, a local merchant who was also an ardent collector of mineral and archaeological specimens (Anonymous, 1885). Stephenson had posted a reward for any and all interesting specimens brought in by local farmers, amoung which were included “green bolts” (the emeralds for which the region would later become renowned) and yellowish green transparent crystals which were found loose in the soil with the emeralds. Initially, the yellowish to greenish-yellow hiddenites were thought to be gemmy diopside, and Stephenson sent the specimens to Norman Spang of Pittsburg, PA, a prominent US mineral collector of the era. Soon afterwards, Stephenson brought the discovery to the attention of William Earl Hidden, who had been commissioned by Thomas Edison to search for any sources of platinum in North Carolina (an effort that was, in and of itself, stunningly unsuccessful). Hidden sent samples of the odd green material to John Lawrence Smith, a prominent chemist and mineralogist of Louisville, Kentucky. Smith correctly identified the specimens as being spodumene, and named them “hiddenite” in honor of Hidden. During the hey-day of hiddenite mining in the 1880’s and 1890’s it was also known as “lithia emerald”. <br />
<br />
Hidden recognized the value of the emeralds and the potential of the new gemmy green spodumene. He acquired a tract of poor quality land from J Washington Warren, which was either the site of the initial discovery or near to it, for $1500 (the sale price was approximately three times the value of the land). The Emerald and Hiddenite Mining Company was organized and excavations on the site quickly recovered loose hiddenites and emeralds in the red, gravelly clay. At a depth of about 26 feet they struck bedrock and soon were uncovering hiddenites from solid rock. Oddly, period newspaper accounts and statements by Kunz (1892) indicate that mining on the site was never undertaken as a full time operation, but was only prosecuted a few weeks or months during the summer. Writing in 1892, Kunz described the hiddenite being recovered as “always transparent, ranges from colorless (rare) to a light yellow, into a yellowish green, then into a deep yellow emerald green. Sometimes an entire crystal has a uniform green color, but generally one end is yellow and the other green.” He added “The yellow color exhibited by the mineral in even the darkest green gems will prevent it from competing with the emerald, since it is this very quality that has kept down the prices of the Siberian demantoids or Uralian emeralds as the green garnets are variously termed. Dr. J Lawrence Smith says that the crystals, when cut and polished, resemble the emerald in luster, though the color is not so intense as in the finer variety of the latter gem. Prof. Edward S Dana says that, owing to its dichroism, it has a peculiar brilliancy which is wanting in the true emerald.” Kunz noted that the finest crystal recovered prior to 1892 measured 68 mm by 8 mm, and could have cut a gem of 5.5ct estimated weight. The size of most cut gems were small, with a 2ct hiddenite in the Augustus C. Hamlin collection being considered amoung the finest of the large stones. Between 1880 and 1888 approximately $7,500 worth of hiddenite was produced, with values ranging from $40 to $100 a carat (1892 US dollars). <br />
<br />
References:<br />
<br />
Anonymous (1885): “Taylorsville And Aleck, Their Resources and Advantages, Their Enterprise and Progress” <br />
The Landmark (newspaper), 8 May 1885<br />
<br />
Davidson, S. C. (1927) American Mineralogist Vol. 27, pp 305-307 “The Hiddenite Occurrence in North Carolina”<br />
<br />
J.L.Smith (1881) American Journal of Science Vol. 21 ser 3 pp128-30 (1881)"Hiddenite, an emerald-green variety of spodumene" <br />
<br />
Palache, C., Davidson, S. C., and Goranson, E.A. (1930) American Mineralogist Vol 15 No. 8 p. 280 The Hiddenite deposit in Alexander County, N.Carolina"</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Table_Of_Contents&diff=5034Table Of Contents2007-01-09T03:21:01Z<p>Russell: </p>
<hr />
<div>In this TOC (Table Of Content) you will find pages that have been published presented in blue and pages that yet need to be written presented in red. For better navigation, we list the pages in 3 categories:<br />
#Theory - Basic and in-depth mechanisms involved in gemology<br />
#Practical - Descriptions of instruments, techniques and other practical discussions<br />
#Gemstones - Information about the gemstone at hand<br />
<br />
For the neophyte it is best to start in that order as some words and principles introduced in the theory pages will need to be understood first. At the very least, one should learn the theory in the "basic" sections of the pages.<br /><br />
Although gemology is not rocket science, some science and math is involved. We don't believe in the dumbing-down of gemology, so you should be ready and willing to expand your horizons. If you find any of the technical concepts difficult to visualize or grasp, go to the forum (the link is above) and ask. We will help you with it, and at the same time you will help this project become more complete for those who come after you. <br />
<br />
We never said it was going to be easy. But it's a heck of an interesting ride.<br />
<br />
<br />
{| {{toctable}} width="100%"<br />
<br />
!Theory <br />
!Practical<br />
!Gemstones<br />
<br />
|-<br />
<br />
|style="padding-right:5px" valign="top"|<br />
:'''Content'''<br />
#[[Introduction to Gemology]]<br />
##[[Introduction_to_Gemology#Education|Education]]<br />
##[[An Historical Look at our Obsession with Gems]]<br />
##[[Glossary of Terms]]<br />
#[[Origins of minerals]]<br />
##[[Origins_of_minerals#Igneous_.28Magmatic.29_rocks|Igneous rocks]]<br />
##[[Origins_of_minerals#Sedimentary_rocks|Sedimentary rocks]]<br />
##[[Origins_of_minerals#Metamorphic_rocks|Metamorphic rocks]]<br />
#[[The Chemistry of Gemstones]]<br />
##[[Isomorphous replacement]]<br />
##[[The Chemical Classification of Gems & Minerals]]<br />
#[[Crystallography]]<br />
##[[Crystal Systems]]<br />
##[[Form]]<br />
##[[Habit]]<br />
##[[Symmetry]]<br />
##[[Twinning]]<br />
#[[Cleavage]]<br />
#[[Cleavage#Parting|Parting]]<br />
#[[Cleavage#Fracture|Fracture]]<br />
#[[Optical properties of gemstones]]<br />
##[[Nature of light]]<br />
###[[Nature_of_light#The_electromagnetic_wave_theory |The electromagnetic wave theory]]<br />
###[[Nature_of_light#The_quantum_theory |The quantum theory]]<br />
###[[Nature_of_light#The_electromagnetic_spectrum |The electromagnetic spectrum]]<br />
##[[Reflection effects]]<br />
###[[Luster]]<br />
###[[Sheen]]<br />
####[[Sheen#Chatoyancy | Chatoyancy]]<br />
####[[Sheen#Asterism | Asterism]]<br />
####[[Sheen#Iridescence | Iridescence]]<br />
###[[Brilliance | Brilliance (Total Internal Reflection)]]<br />
##[[Polarization]]<br />
##[[Pleochroism]]<br />
##[[Color]]<br />
###[[Causes of color]]<br />
##[[Refraction]]<br />
###[[Double Refraction]]<br />
##[[Dispersion]]<br />
##[[Diffraction]]<br />
##[[Interference]]<br />
##[[Luminescence]]<br />
###[[Luminescence#Fluorescence | Fluorescence]]<br />
###[[Luminescence#Phosphorescence | Phosphorescence]]<br />
###[[Luminescence#Tenebrescence | Tenebrescence]]<br />
###[[Luminescence#Triboluminescence | Triboluminescence]]<br />
#[[Hardness]]<br />
#[[Specific Gravity]]<br />
#[[Math| Basic math for gemology]]<br />
##[[Math#Cross-multiplication | Cross-multiplication]]<br />
##[[Math#Sine.2C_cosine_and_tangent | Sine, cosine and tangent]]<br />
##[[Math#Degrees.2C_minutes_and_seconds | Degrees, minutes and seconds]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
#[[Equipment used to identify gemstones]]<br />
##[[10x Loupe]]<br />
##[[Spectroscope]]<br />
##[[Refractometer]]<br />
##[[Polariscope]]<br />
##[[Dichroscope]]<br />
##[[Immersion Cell]]<br />
##[[Color Filters]]<br />
##[[Microscope]]<br />
##[[Hydrostatic Balance]]<br />
##[[Heavy Liquids]]<br />
##[[Hardness#Hardness_pencils|Hardness pencils]]<br />
#[[Inclusions]]<br />
#[[Synthetic gemstones]]<br />
#[[Visual Optics]]<br />
##[[The Hodgkinson Method]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
*[[Alphabetic list by gemstone name]]<br />
#[[Diamond]]<br />
#[[Corundum]]<br />
##[[Ruby]]<br />
##[[Sapphire]]<br />
#[[Beryl]]<br />
##[[Aquamarine]]<br />
##[[Bixbite]]<br />
##[[Emerald]]<br />
###[[Vanadium Beryl]]<br />
##[[Goshenite]]<br />
##[[Green Beryl]]<br />
##[[Heliodor]]<br />
##[[Maxixe]]<br />
##[[Morganite]]<br />
##[[Riesling]]<br />
##[[True Blue]]<br />
##[[Pezzottaite]] (Beryl Group)<br />
#[[Quartz]]<br />
##[[Amethyst]]<br />
##[[Ametrine]]<br />
##[[Citrine]]<br />
##[[Prasiolite]]<br />
##[[Rock Crystal]]<br />
##[[Rose Quartz]]<br />
##[[Smokey Quartz]]<br />
#[[Quartz - Microcrystalline]]<br />
##[[Chalcedony]]<br />
###[[Agate]]<br />
###[[Bloodstone]]<br />
###[[Carnelian]]<br />
###[[Chrysoprase]]<br />
###[[Jasper]]<br />
###[[Onyx]]<br />
###[[Sard]]<br />
###[[Sardonyx]]<br />
###[[Tigereye]]<br />
#[[Zoisite]]<br />
##[[Tanzanite]]<br />
##[[Thulite]]<br />
#[[Garnet]]<br />
##[[Almandine]]<br />
##[[Andradite]]<br />
###[[Andradite#Demantoid|Demantoid]]<br />
##[[Grossular]]<br />
###[[Grossular#Chrome_grossular|Chrome grossular]]<br />
###[[Grossular#Hessonite|Hessonite]]<br />
###[[Grossular#Hydrogrossular |Hydrogrossular]]<br />
###[[Grossular#Mali|Mali]]<br />
###[[Grossular#Tsavorite|Tsavorite]]<br />
##[[Pyrope]]<br />
##[[Spessartite]]<br />
##[[Uvarovite]]<br />
#[[Diopside]]<br />
##[[Chrome Diopside]]<br />
##[[Tashmarine]]&trade;<br />
#[[Feldspar]]<br />
##[[Amazonite]]<br />
##[[Andesine]]<br />
##[[Labradorite]]<br />
##[[Moonstone]]<br />
##[[Spectrolite]]<br />
##[[Sunstone]]<br />
#[[Spodumene]]<br />
##[[Hiddenite]]<br />
##[[Kunzite]]<br />
#[[Chrysoberyl]]<br />
##[[Alexandrite]]<br />
#[[Spinel]]<br />
#[[Tourmaline]]<br />
##[[Chrome]]<br />
##[[Indicolite]]<br />
##[[Liddicoatite]]<br />
##[[Paraiba type]]<br />
##[[Rubellite]]<br />
#[[Amber]]<br />
#[[Ammolite]]<br />
#[[Anatase]]<br />
#[[Andalusite]]<br />
#[[Apatite]]<br />
#[[Benitoite]]<br />
#[[Bowenite]]<br />
#[[Charoite]]<br />
#[[Chrysocolla]]<br />
#[[Coral]]<br />
#[[Danburite]]<br />
#[[Datolite]]<br />
#[[Dioptase]]<br />
#[[Enstatite]]<br />
#[[Fluorite]]<br />
#[[Glass]]<br />
##[[Goldstone]]<br />
#[[Hauyne]]<br />
#[[Iolite]]<br />
#[[Jade]]<br />
##[[Jadeite]]<br />
##[[Nephrite]]<br />
#[[Konerupine]]<br />
#[[Lapis Lazuli]]<br />
#[[Larimar]]<br />
#[[Maw-sit-sit]]<br />
#[[Opal]]<br />
##[[Black Opal]]<br />
##[[Blue Peruvian Opal]]<br />
##[[Boulder Opal]]<br />
##[[Fire Opal]]<br />
#[[Pearl]]<br />
##[[Salt water]]<br />
###[[Akoya]]<br />
###[[Tahitian]]<br />
###[[South Sea]]<br />
###[[Mabé]]<br />
###[[Conch Pearl]]<br />
###[[Melo Pearl]]<br />
###[[Quahog]]<br />
##[[Freshwater Pearl]]<br />
###[[Kasumiga pearls]]<br />
###[[Chinese freshwater pearls]]<br />
#[[Peridot]]<br />
#[[Poudretteite]]<br />
#[[Scapolite]]<br />
#[[Sodalite]]<br />
##[[Hackmanite]]<br />
#[[Sphalerite]]<br />
#[[Sphene]]<br />
#[[Topaz]]<br />
#[[Turquoise]]<br />
#[[Vesuvianite]]<br />
#[[Zircon]]<br />
<br />
<br />
<br />
|}</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Zincite&diff=5033Zincite2007-01-09T03:18:45Z<p>Russell: </p>
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</head><br />
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<body bgcolor=white lang=EN-US link=blue vlink=purple style='tab-interval:.5in'><br />
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<div class=Section1><br />
<br />
<p class=MsoNormal><span class=SpellE><b style='mso-bidi-font-weight:normal'><span<br />
style='font-size:18.0pt;color:windowtext'>Zincite</span></b></span><b<br />
style='mso-bidi-font-weight:normal'><span style='font-size:18.0pt;color:windowtext'><o:p></o:p></span></b></p><br />
<br />
<p class=MsoNormal><span style='color:windowtext'>Non-members can contribute to<br />
this topic through the <a href="http://gemologyproject.com/wiki/submission.php">submission</a><br />
page. <o:p></o:p></span></p><br />
<br />
<table class=MsoNormalTable border=1 cellpadding=0 align=right width=250<br />
style='width:187.5pt;mso-cellspacing:1.5pt;mso-table-lspace:2.25pt;mso-table-rspace:<br />
2.25pt;mso-table-anchor-vertical:paragraph;mso-table-anchor-horizontal:column;<br />
mso-table-left:right;mso-table-top:middle'><br />
<tr style='mso-yfti-irow:0;mso-yfti-firstrow:yes'><br />
<td colspan=2 style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal align=center style='text-align:center;mso-element:frame;<br />
mso-element-frame-hspace:2.25pt;mso-element-wrap:around;mso-element-anchor-vertical:<br />
paragraph;mso-element-anchor-horizontal:column;mso-element-left:right;<br />
mso-element-top:middle;mso-height-rule:exactly'><span class=SpellE><b><span<br />
style='color:windowtext'>Zincite</span></b></span><b><span style='color:windowtext'><o:p></o:p></span></b></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:1'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Chemical composition <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>(<span class=SpellE>Zn,Mn</span>)0<o:p></o:p></span></p><br />
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;<br />
mso-element:frame;mso-element-frame-hspace:2.25pt;mso-element-wrap:around;<br />
mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:column;<br />
mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Zinc manganese oxide <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:2'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><st1:City<br />
w:st="on"><st1:place w:st="on"><span style='color:windowtext'>Crystal</span></st1:place></st1:City><span<br />
style='color:windowtext'> system <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>hexagonal<o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:3'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Habit <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Pyramidal (<span class=SpellE>hemihedral</span>);<br />
massive<o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:4'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Cleavage <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Perfect on {10-10}; Parting on {0001} <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:5'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Fracture <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
class=SpellE><span style='color:windowtext'>conchoidal</span></span><span<br />
style='color:windowtext'> <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:6'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Hardness <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>4 <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:7'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Optic nature <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
class=SpellE><span style='color:windowtext'>Uniaxial</span></span><span<br />
style='color:windowtext'> + <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:8'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Refractive index <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>2.013 &#8211; 2.029 <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:9'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Birefringence <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'><o:p>&nbsp;</o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:10'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Dispersion <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'><o:p>&nbsp;</o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:11'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Specific gravity <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>5.66 <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:12'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
class=SpellE><span style='color:windowtext'>Lustre</span></span><span<br />
style='color:windowtext'> <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
class=SpellE><span style='color:windowtext'>Sunadamantine</span></span><span<br />
style='color:windowtext'> to resinous <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:13'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
class=SpellE><span style='color:windowtext'>Pleochroism</span></span><span<br />
style='color:windowtext'> <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'><o:p>&nbsp;</o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:14;mso-yfti-lastrow:yes'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Fluorescence <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Pale yellow <i style='mso-bidi-font-style:normal'>(Extremely<br />
rare!)</i> <o:p></o:p></span></p><br />
</td><br />
</tr><br />
</table><br />
<br />
<table class=MsoNormalTable border=0 cellpadding=0 style='mso-cellspacing:1.5pt'><br />
<tr style='mso-yfti-irow:0;mso-yfti-firstrow:yes;mso-yfti-lastrow:yes'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;<br />
mso-outline-level:2'><b><span style='font-size:18.0pt;color:windowtext'>Contents<o:p></o:p></span></b></p><br />
<p class=MsoNormal><span style='color:windowtext'>[<a<br />
href="javascript:toggleToc()">hide</a>]<o:p></o:p></span></p><br />
<ul type=disc><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1;tab-stops:list .5in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Chemical_composition">1<br />
Chemical composition</a><o:p></o:p></li><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1;tab-stops:list .5in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Diagnostics">2<br />
Diagnostics</a> <o:p></o:p></li><br />
<ul type=circle><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level2 lfo1;tab-stops:list 1.0in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Color">2.1<br />
Color</a><o:p></o:p></li><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level2 lfo1;tab-stops:list 1.0in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Refractive_index">2.2<br />
Refractive index</a><o:p></o:p></li><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level2 lfo1;tab-stops:list 1.0in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Specific_gravity">2.3<br />
Specific gravity</a><o:p></o:p></li><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level2 lfo1;tab-stops:list 1.0in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Fluorescence">2.4<br />
Fluorescence</a><o:p></o:p></li><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level2 lfo1;tab-stops:list 1.0in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Spectroscope">2.5<br />
Spectroscope</a><o:p></o:p></li><br />
</ul><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1;tab-stops:list .5in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Treatments">3<br />
Treatments</a><o:p></o:p></li><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1;tab-stops:list .5in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Occurence">4<br />
<span class=SpellE>Occurence</span></a><o:p></o:p></li><br />
</ul><br />
</td><br />
</tr><br />
</table><br />
<br />
<p class=MsoNormal><span style='color:windowtext'><script type="text/javascript"><br />
if (window.showTocToggle) { var tocShowText = "show"; var tocHideText = "hide"; showTocToggle(); } <br />
</script>[<a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite&amp;action=edit&amp;section=1"<br />
title=Danburite><span class=GramE>edit</span></a>]<o:p></o:p></span></p><br />
<br />
<p><a name="Chemical_composition"></a><strong><span style='font-size:13.5pt'>Crystal<br />
System</span></strong><span style='font-size:13.5pt'>:<span<br />
style='mso-spacerun:yes'>&nbsp; </span></span>hexagonal</p><br />
<br />
<p><strong><span style='font-size:13.5pt'>Crystal Habit</span></strong><span<br />
style='font-size:13.5pt'>: </span>crystals pyramidal and distinctly <span<br />
class=SpellE>hemimorphic</span>; massive</p><br />
<br />
<p><strong><span style='font-size:13.5pt'>Composition</span></strong><strong><span<br />
style='font-weight:normal;mso-bidi-font-weight:bold'>: zinc oxide, <span<br />
class=SpellE>ZnO</span>. Usually with minor amounts of manganese (less than<br />
7%), and minor to trace amounts of iron, magnesium and aluminum. <o:p></o:p></span></strong></p><br />
<br />
<p><strong><u><span style='font-size:18.0pt'>Diagnostics</span></u></strong><span<br />
style='font-size:18.0pt'>:<o:p></o:p></span></p><br />
<br />
<p><span style='font-size:18.0pt'><span style='mso-tab-count:1'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span>Because<br />
of its high specific gravity, <span class=SpellE>zincite</span> is unlikely to<br />
be confused with any other gem material. </p><br />
<br />
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><br />
<br />
<p><strong>Color:</strong> Deep red, deep orange. <strong><span<br />
style='font-weight:normal;mso-bidi-font-weight:bold'>Manganese is the coloring<br />
agent. Green <span class=SpellE>zincite</span> has been observed in nature but<br />
to date has not been found in sizes sufficient to facet.<o:p></o:p></span></strong></p><br />
<br />
<p><strong>Magnification: </strong><strong><span style='font-weight:normal;<br />
mso-bidi-font-weight:bold'>black <span class=SpellE>submetallic</span><br />
inclusions of franklinite or <span class=SpellE>hetaerolite</span> (both oxides<br />
containing zinc and manganese) are common<o:p></o:p></span></strong></p><br />
<br />
<p><strong>Optical and Physical Properties:</strong></p><br />
<br />
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><br />
<br />
<p><strong>Cleavage: </strong><strong><span style='font-weight:normal;<br />
mso-bidi-font-weight:bold'>perfect on</span> </strong>{10-<span class=o>1</span>0<span<br />
class=GramE>} ;</span> parting on {000-1}<br><br />
<strong>Fracture: <span class=SpellE>conchoidal</span></strong><b><br><br />
<strong>Specific Gravity</strong></b>:<span style='mso-spacerun:yes'>&nbsp;<br />
</span>5.66 (measured) 5.67 (calculated)<br><br />
<strong>Hardness</strong>: 4<br><br />
<span class=SpellE><strong>Lustre</strong></span><strong>:<span<br />
style='mso-spacerun:yes'>&nbsp; </span></strong><span class=SpellE><strong><span<br />
style='font-weight:normal;mso-bidi-font-weight:bold'>subadamantine</span></strong></span><strong><span<br />
style='font-weight:normal;mso-bidi-font-weight:bold'> to resinous</span></strong><b><br><br />
<strong>Optical Nature</strong></b>:<span style='mso-spacerun:yes'>&nbsp;<br />
</span><span class=SpellE>uniaxial</span> (+)<br><br />
<strong>Refractive Index</strong>: &#949; = 2.013<span<br />
style='mso-spacerun:yes'>&nbsp; </span>&#969; = 2.029<br><br />
<strong>Birefringence</strong>: <span<br />
style='mso-spacerun:yes'>&nbsp;&nbsp;</span><br><br />
<b style='mso-bidi-font-weight:normal'>D<strong>ispersion</strong></b>: <br><br />
<span class=SpellE><strong>Pleochroism</strong></span>:<br><br />
<strong>Spectroscope:</strong></p><br />
<br />
</blockquote><br />
<br />
</blockquote><br />
<br />
<p><strong><u><span style='font-size:18.0pt'>Treatments</span></u></strong><strong><span<br />
style='font-size:18.0pt'>: </span></strong><strong><span style='font-weight:<br />
normal;mso-bidi-font-weight:bold'>none known</span></strong><b<br />
style='mso-bidi-font-weight:normal'><o:p></o:p></b></p><br />
<br />
<p><strong><u><span style='font-size:18.0pt'>Phenomenon</span></u></strong><span<br />
style='font-size:18.0pt'>: </span><span class=SpellE>zincite</span> may, in <b<br />
style='mso-bidi-font-weight:normal'><i style='mso-bidi-font-style:normal'>extremely</i></b><br />
rarely instances, display a pale yellow fluorescence in long wave ultraviolet<br />
light. This has not yet been documented in cut stones.<br><br />
<br><br />
<strong><u><span style='font-size:18.0pt'>Synthetics</span></u></strong><span<br />
style='font-size:18.0pt'>:<o:p></o:p></span></p><br />
<br />
<p>Synthetic <span class=SpellE>zincite</span> flooded the US market in the<br />
late 1980&#8217;s and 1990&#8217;s,<span style='mso-spacerun:yes'>&nbsp;<br />
</span>available in a rainbow of colors from pale green to green, pale red to<br />
deep red, and yellow to deep orange synthetic. This material was derived from<br />
the smokestacks of a metal refinery in <st1:State w:st="on">Silesia</st1:State>,<br />
<st1:country-region w:st="on"><st1:place w:st="on">Poland</st1:place></st1:country-region>,<br />
where it had crystallized over many years from volatized zinc oxide. <span<br />
class=SpellE>Zincite</span> is also grown in laboratories by several<br />
techniques, including hydrothermal, <span class=SpellE>Czochralski</span> pull,<br />
and vapor deposition (sublimation<span class=GramE>)<span<br />
style='mso-spacerun:yes'>&nbsp; </span>methods</span>. </p><br />
<br />
<p><strong><u><span style='font-size:18.0pt'>Imitations</span></u></strong><span<br />
style='font-size:18.0pt'>: </span>none reported</p><br />
<br />
<p><span class=SpellE><strong><u><span style='font-size:18.0pt'>Occurence</span></u></strong></span><span<br />
style='font-size:18.0pt'>: </span>the zinc mines of Franklin and Ogdensburg in <st1:place<br />
w:st="on"><st1:City w:st="on">Sussex County</st1:City>, <st1:State w:st="on">New<br />
Jersey</st1:State></st1:place>.</p><br />
<br />
<p><strong><u><span style='font-size:18.0pt'>Sources</span></u></strong><span<br />
style='font-size:18.0pt'>:<o:p></o:p></span></p><br />
<br />
<p>Anthony, John W., <span class=SpellE>Bideaux</span>, Richard A., <span<br />
class=SpellE>Bladh</span>, Kenneth W., and Nichols, Monte C. (1990): Handbook<br />
of Mineralogy: Mineral Data Publishing, <st1:place w:st="on"><st1:City w:st="on">Tucson</st1:City>,<br />
<st1:State w:st="on">Arizona</st1:State></st1:place>,</p><br />
<br />
<p>Dunn, Pete J. (1995) <st1:City w:st="on"><i>Franklin</i></st1:City><i> and <st1:place<br />
w:st="on"><st1:City w:st="on">Sterling Hill</st1:City>, <st1:State w:st="on">New<br />
Jersey</st1:State></st1:place>: the world&#8217;s most magnificent mineral<br />
deposits</i> </p><br />
<br />
<p><span class=SpellE>Palache</span>, C. (1935), Minerals of <st1:City w:st="on">Franklin</st1:City><br />
and <st1:place w:st="on"><st1:City w:st="on">Sterling Hill</st1:City>, <st1:State<br />
w:st="on">New Jersey</st1:State></st1:place>, USG Professional Paper 180</p><br />
<br />
<p><span class=SpellE>Palache</span>, Charles, Harry Berman &amp; Clifford <span<br />
class=SpellE>Frondel</span> (1944), The System of Mineralogy of James Dwight<br />
Dana and <st1:place w:st="on"><st1:PlaceName w:st="on">Edward</st1:PlaceName> <st1:PlaceName<br />
w:st="on">Salisbury</st1:PlaceName> <st1:PlaceName w:st="on">Dana</st1:PlaceName><br />
<st1:PlaceName w:st="on">Yale</st1:PlaceName> <st1:PlaceType w:st="on">University</st1:PlaceType></st1:place><br />
1837-1892, Seventh edition<br style='mso-special-character:line-break'><br />
<![if !supportLineBreakNewLine]><br style='mso-special-character:line-break'><br />
<![endif]></p><br />
<br />
<p><strong><u><span style='font-size:18.0pt'>External Links</span></u></strong><strong><span<br />
style='font-size:18.0pt'>:</span></strong></p><br />
<br />
</div><br />
<br />
</body><br />
<br />
</html></div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Zincite&diff=5032Zincite2007-01-09T03:17:01Z<p>Russell: </p>
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</head><br />
<br />
<body bgcolor=white lang=EN-US link=blue vlink=purple style='tab-interval:.5in'><br />
<br />
<div class=Section1><br />
<br />
<p class=MsoNormal><span class=SpellE><b style='mso-bidi-font-weight:normal'><span<br />
style='font-size:18.0pt;color:windowtext'>Zincite</span></b></span><b<br />
style='mso-bidi-font-weight:normal'><span style='font-size:18.0pt;color:windowtext'><o:p></o:p></span></b></p><br />
<br />
<p class=MsoNormal><span style='color:windowtext'>Non-members can contribute to<br />
this topic through the <a href="http://gemologyproject.com/wiki/submission.php">submission</a><br />
page. <o:p></o:p></span></p><br />
<br />
<table class=MsoNormalTable border=0 cellpadding=0 align=right width=250<br />
style='width:187.5pt;mso-cellspacing:1.5pt;mso-table-lspace:2.25pt;mso-table-rspace:<br />
2.25pt;mso-table-anchor-vertical:paragraph;mso-table-anchor-horizontal:column;<br />
mso-table-left:right;mso-table-top:middle'><br />
<tr style='mso-yfti-irow:0;mso-yfti-firstrow:yes'><br />
<td colspan=2 style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal align=center style='text-align:center;mso-element:frame;<br />
mso-element-frame-hspace:2.25pt;mso-element-wrap:around;mso-element-anchor-vertical:<br />
paragraph;mso-element-anchor-horizontal:column;mso-element-left:right;<br />
mso-element-top:middle;mso-height-rule:exactly'><span class=SpellE><b><span<br />
style='color:windowtext'>Zincite</span></b></span><b><span style='color:windowtext'><o:p></o:p></span></b></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:1'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Chemical composition <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>(<span class=SpellE>Zn,Mn</span>)0<o:p></o:p></span></p><br />
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;<br />
mso-element:frame;mso-element-frame-hspace:2.25pt;mso-element-wrap:around;<br />
mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:column;<br />
mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Zinc manganese oxide <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:2'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><st1:City<br />
w:st="on"><st1:place w:st="on"><span style='color:windowtext'>Crystal</span></st1:place></st1:City><span<br />
style='color:windowtext'> system <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>hexagonal<o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:3'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Habit <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Pyramidal (<span class=SpellE>hemihedral</span>);<br />
massive<o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:4'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Cleavage <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Perfect on {10-10}; Parting on {0001} <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:5'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Fracture <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
class=SpellE><span style='color:windowtext'>conchoidal</span></span><span<br />
style='color:windowtext'> <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:6'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Hardness <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>4 <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:7'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Optic nature <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
class=SpellE><span style='color:windowtext'>Uniaxial</span></span><span<br />
style='color:windowtext'> + <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:8'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Refractive index <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>2.013 &#8211; 2.029 <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:9'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Birefringence <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'><o:p>&nbsp;</o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:10'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Dispersion <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'><o:p>&nbsp;</o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:11'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Specific gravity <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>5.66 <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:12'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
class=SpellE><span style='color:windowtext'>Lustre</span></span><span<br />
style='color:windowtext'> <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
class=SpellE><span style='color:windowtext'>Sunadamantine</span></span><span<br />
style='color:windowtext'> to resinous <o:p></o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:13'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
class=SpellE><span style='color:windowtext'>Pleochroism</span></span><span<br />
style='color:windowtext'> <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'><o:p>&nbsp;</o:p></span></p><br />
</td><br />
</tr><br />
<tr style='mso-yfti-irow:14;mso-yfti-lastrow:yes'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Fluorescence <o:p></o:p></span></p><br />
</td><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:2.25pt;<br />
mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:<br />
column;mso-element-left:right;mso-element-top:middle;mso-height-rule:exactly'><span<br />
style='color:windowtext'>Pale yellow <i style='mso-bidi-font-style:normal'>(Extremely<br />
rare!)</i> <o:p></o:p></span></p><br />
</td><br />
</tr><br />
</table><br />
<br />
<table class=MsoNormalTable border=0 cellpadding=0 style='mso-cellspacing:1.5pt'><br />
<tr style='mso-yfti-irow:0;mso-yfti-firstrow:yes;mso-yfti-lastrow:yes'><br />
<td style='padding:.75pt .75pt .75pt .75pt'><br />
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;<br />
mso-outline-level:2'><b><span style='font-size:18.0pt;color:windowtext'>Contents<o:p></o:p></span></b></p><br />
<p class=MsoNormal><span style='color:windowtext'>[<a<br />
href="javascript:toggleToc()">hide</a>]<o:p></o:p></span></p><br />
<ul type=disc><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1;tab-stops:list .5in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Chemical_composition">1<br />
Chemical composition</a><o:p></o:p></li><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1;tab-stops:list .5in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Diagnostics">2<br />
Diagnostics</a> <o:p></o:p></li><br />
<ul type=circle><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level2 lfo1;tab-stops:list 1.0in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Color">2.1<br />
Color</a><o:p></o:p></li><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level2 lfo1;tab-stops:list 1.0in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Refractive_index">2.2<br />
Refractive index</a><o:p></o:p></li><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level2 lfo1;tab-stops:list 1.0in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Specific_gravity">2.3<br />
Specific gravity</a><o:p></o:p></li><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level2 lfo1;tab-stops:list 1.0in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Fluorescence">2.4<br />
Fluorescence</a><o:p></o:p></li><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level2 lfo1;tab-stops:list 1.0in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Spectroscope">2.5<br />
Spectroscope</a><o:p></o:p></li><br />
</ul><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1;tab-stops:list .5in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Treatments">3<br />
Treatments</a><o:p></o:p></li><br />
<li class=MsoNormal style='color:windowtext;mso-margin-top-alt:auto;<br />
mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1;tab-stops:list .5in'><a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite#Occurence">4<br />
<span class=SpellE>Occurence</span></a><o:p></o:p></li><br />
</ul><br />
</td><br />
</tr><br />
</table><br />
<br />
<p class=MsoNormal><span style='color:windowtext'><script type="text/javascript"><br />
if (window.showTocToggle) { var tocShowText = "show"; var tocHideText = "hide"; showTocToggle(); } <br />
</script>[<a<br />
href="http://gemologyproject.com/wiki/index.php?title=Danburite&amp;action=edit&amp;section=1"<br />
title=Danburite><span class=GramE>edit</span></a>]<o:p></o:p></span></p><br />
<br />
<p><a name="Chemical_composition"></a><strong><span style='font-size:13.5pt'>Crystal<br />
System</span></strong><span style='font-size:13.5pt'>:<span<br />
style='mso-spacerun:yes'>&nbsp; </span></span>hexagonal</p><br />
<br />
<p><strong><span style='font-size:13.5pt'>Crystal Habit</span></strong><span<br />
style='font-size:13.5pt'>: </span>crystals pyramidal and distinctly <span<br />
class=SpellE>hemimorphic</span>; massive</p><br />
<br />
<p><strong><span style='font-size:13.5pt'>Composition</span></strong><strong><span<br />
style='font-weight:normal;mso-bidi-font-weight:bold'>: zinc oxide, <span<br />
class=SpellE>ZnO</span>. Usually with minor amounts of manganese (less than<br />
7%), and minor to trace amounts of iron, magnesium and aluminum. <o:p></o:p></span></strong></p><br />
<br />
<p><strong><u><span style='font-size:18.0pt'>Diagnostics</span></u></strong><span<br />
style='font-size:18.0pt'>:<o:p></o:p></span></p><br />
<br />
<p><span style='font-size:18.0pt'><span style='mso-tab-count:1'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span>Because<br />
of its high specific gravity, <span class=SpellE>zincite</span> is unlikely to<br />
be confused with any other gem material. </p><br />
<br />
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><br />
<br />
<p><strong>Color:</strong> Deep red, deep orange. <strong><span<br />
style='font-weight:normal;mso-bidi-font-weight:bold'>Manganese is the coloring<br />
agent. Green <span class=SpellE>zincite</span> has been observed in nature but<br />
to date has not been found in sizes sufficient to facet.<o:p></o:p></span></strong></p><br />
<br />
<p><strong>Magnification: </strong><strong><span style='font-weight:normal;<br />
mso-bidi-font-weight:bold'>black <span class=SpellE>submetallic</span><br />
inclusions of franklinite or <span class=SpellE>hetaerolite</span> (both oxides<br />
containing zinc and manganese) are common<o:p></o:p></span></strong></p><br />
<br />
<p><strong>Optical and Physical Properties:</strong></p><br />
<br />
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><br />
<br />
<p><strong>Cleavage: </strong><strong><span style='font-weight:normal;<br />
mso-bidi-font-weight:bold'>perfect on</span> </strong>{10-<span class=o>1</span>0<span<br />
class=GramE>} ;</span> parting on {000-1}<br><br />
<strong>Fracture: <span class=SpellE>conchoidal</span></strong><b><br><br />
<strong>Specific Gravity</strong></b>:<span style='mso-spacerun:yes'>&nbsp;<br />
</span>5.66 (measured) 5.67 (calculated)<br><br />
<strong>Hardness</strong>: 4<br><br />
<span class=SpellE><strong>Lustre</strong></span><strong>:<span<br />
style='mso-spacerun:yes'>&nbsp; </span></strong><span class=SpellE><strong><span<br />
style='font-weight:normal;mso-bidi-font-weight:bold'>subadamantine</span></strong></span><strong><span<br />
style='font-weight:normal;mso-bidi-font-weight:bold'> to resinous</span></strong><b><br><br />
<strong>Optical Nature</strong></b>:<span style='mso-spacerun:yes'>&nbsp;<br />
</span><span class=SpellE>uniaxial</span> (+)<br><br />
<strong>Refractive Index</strong>: &#949; = 2.013<span<br />
style='mso-spacerun:yes'>&nbsp; </span>&#969; = 2.029<br><br />
<strong>Birefringence</strong>: <span<br />
style='mso-spacerun:yes'>&nbsp;&nbsp;</span><br><br />
<b style='mso-bidi-font-weight:normal'>D<strong>ispersion</strong></b>: <br><br />
<span class=SpellE><strong>Pleochroism</strong></span>:<br><br />
<strong>Spectroscope:</strong></p><br />
<br />
</blockquote><br />
<br />
</blockquote><br />
<br />
<p><strong><u><span style='font-size:18.0pt'>Treatments</span></u></strong><strong><span<br />
style='font-size:18.0pt'>: </span></strong><strong><span style='font-weight:<br />
normal;mso-bidi-font-weight:bold'>none known</span></strong><b<br />
style='mso-bidi-font-weight:normal'><o:p></o:p></b></p><br />
<br />
<p><strong><u><span style='font-size:18.0pt'>Phenomenon</span></u></strong><span<br />
style='font-size:18.0pt'>: </span><span class=SpellE>zincite</span> may, in <b<br />
style='mso-bidi-font-weight:normal'><i style='mso-bidi-font-style:normal'>extremely</i></b><br />
rarely instances, display a pale yellow fluorescence in long wave ultraviolet<br />
light. This has not yet been documented in cut stones.<br><br />
<br><br />
<strong><u><span style='font-size:18.0pt'>Synthetics</span></u></strong><span<br />
style='font-size:18.0pt'>:<o:p></o:p></span></p><br />
<br />
<p>Synthetic <span class=SpellE>zincite</span> flooded the US market in the<br />
late 1980&#8217;s and 1990&#8217;s,<span style='mso-spacerun:yes'>&nbsp;<br />
</span>available in a rainbow of colors from pale green to green, pale red to<br />
deep red, and yellow to deep orange synthetic. This material was derived from<br />
the smokestacks of a metal refinery in <st1:State w:st="on">Silesia</st1:State>,<br />
<st1:country-region w:st="on"><st1:place w:st="on">Poland</st1:place></st1:country-region>,<br />
where it had crystallized over many years from volatized zinc oxide. <span<br />
class=SpellE>Zincite</span> is also grown in laboratories by several<br />
techniques, including hydrothermal, <span class=SpellE>Czochralski</span> pull,<br />
and vapor deposition (sublimation<span class=GramE>)<span<br />
style='mso-spacerun:yes'>&nbsp; </span>methods</span>. </p><br />
<br />
<p><strong><u><span style='font-size:18.0pt'>Imitations</span></u></strong><span<br />
style='font-size:18.0pt'>: </span>none reported</p><br />
<br />
<p><span class=SpellE><strong><u><span style='font-size:18.0pt'>Occurence</span></u></strong></span><span<br />
style='font-size:18.0pt'>: </span>the zinc mines of Franklin and Ogdensburg in <st1:place<br />
w:st="on"><st1:City w:st="on">Sussex County</st1:City>, <st1:State w:st="on">New<br />
Jersey</st1:State></st1:place>.</p><br />
<br />
<p><strong><u><span style='font-size:18.0pt'>Sources</span></u></strong><span<br />
style='font-size:18.0pt'>:<o:p></o:p></span></p><br />
<br />
<p>Anthony, John W., <span class=SpellE>Bideaux</span>, Richard A., <span<br />
class=SpellE>Bladh</span>, Kenneth W., and Nichols, Monte C. (1990): Handbook<br />
of Mineralogy: Mineral Data Publishing, <st1:place w:st="on"><st1:City w:st="on">Tucson</st1:City>,<br />
<st1:State w:st="on">Arizona</st1:State></st1:place>,</p><br />
<br />
<p>Dunn, Pete J. (1995) <st1:City w:st="on"><i>Franklin</i></st1:City><i> and <st1:place<br />
w:st="on"><st1:City w:st="on">Sterling Hill</st1:City>, <st1:State w:st="on">New<br />
Jersey</st1:State></st1:place>: the world&#8217;s most magnificent mineral<br />
deposits</i> </p><br />
<br />
<p><span class=SpellE>Palache</span>, C. (1935), Minerals of <st1:City w:st="on">Franklin</st1:City><br />
and <st1:place w:st="on"><st1:City w:st="on">Sterling Hill</st1:City>, <st1:State<br />
w:st="on">New Jersey</st1:State></st1:place>, USG Professional Paper 180</p><br />
<br />
<p><span class=SpellE>Palache</span>, Charles, Harry Berman &amp; Clifford <span<br />
class=SpellE>Frondel</span> (1944), The System of Mineralogy of James Dwight<br />
Dana and <st1:place w:st="on"><st1:PlaceName w:st="on">Edward</st1:PlaceName> <st1:PlaceName<br />
w:st="on">Salisbury</st1:PlaceName> <st1:PlaceName w:st="on">Dana</st1:PlaceName><br />
<st1:PlaceName w:st="on">Yale</st1:PlaceName> <st1:PlaceType w:st="on">University</st1:PlaceType></st1:place><br />
1837-1892, Seventh edition<br style='mso-special-character:line-break'><br />
<![if !supportLineBreakNewLine]><br style='mso-special-character:line-break'><br />
<![endif]></p><br />
<br />
<p><strong><u><span style='font-size:18.0pt'>External Links</span></u></strong><strong><span<br />
style='font-size:18.0pt'>:</span></strong></p><br />
<br />
</div><br />
<br />
</body><br />
<br />
</html></div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Table_Of_Contents&diff=5031Table Of Contents2007-01-09T03:12:46Z<p>Russell: </p>
<hr />
<div>In this TOC (Table Of Content) you will find pages that have been published presented in blue and pages that yet need to be written presented in red. For better navigation, we list the pages in 3 categories:<br />
#Theory - Basic and in-depth mechanisms involved in gemology<br />
#Practical - Descriptions of instruments, techniques and other practical discussions<br />
#Gemstones - Information about the gemstone at hand<br />
<br />
For the neophyte it is best to start in that order as some words and principles introduced in the theory pages will need to be understood first. At the very least, one should learn the theory in the "basic" sections of the pages.<br /><br />
Although gemology is not rocket science, some science and math is involved. We don't believe in the dumbing-down of gemology, so you should be ready and willing to expand your horizons. If you find any of the technical concepts difficult to visualize or grasp, go to the forum (the link is above) and ask. We will help you with it, and at the same time you will help this project become more complete for those who come after you. <br />
<br />
We never said it was going to be easy. But it's a heck of an interesting ride.<br />
<br />
<br />
{| {{toctable}} width="100%"<br />
<br />
!Theory <br />
!Practical<br />
!Gemstones<br />
<br />
|-<br />
<br />
|style="padding-right:5px" valign="top"|<br />
:'''Content'''<br />
#[[Introduction to Gemology]]<br />
##[[Introduction_to_Gemology#Education|Education]]<br />
##[[An Historical Look at our Obsession with Gems]]<br />
##[[Glossary of Terms]]<br />
#[[Origins of minerals]]<br />
##[[Origins_of_minerals#Igneous_.28Magmatic.29_rocks|Igneous rocks]]<br />
##[[Origins_of_minerals#Sedimentary_rocks|Sedimentary rocks]]<br />
##[[Origins_of_minerals#Metamorphic_rocks|Metamorphic rocks]]<br />
#[[The Chemistry of Gemstones]]<br />
##[[Isomorphous replacement]]<br />
##[[The Chemical Classification of Gems & Minerals]]<br />
#[[Crystallography]]<br />
##[[Crystal Systems]]<br />
##[[Form]]<br />
##[[Habit]]<br />
##[[Symmetry]]<br />
##[[Twinning]]<br />
#[[Cleavage]]<br />
#[[Cleavage#Parting|Parting]]<br />
#[[Cleavage#Fracture|Fracture]]<br />
#[[Optical properties of gemstones]]<br />
##[[Nature of light]]<br />
###[[Nature_of_light#The_electromagnetic_wave_theory |The electromagnetic wave theory]]<br />
###[[Nature_of_light#The_quantum_theory |The quantum theory]]<br />
###[[Nature_of_light#The_electromagnetic_spectrum |The electromagnetic spectrum]]<br />
##[[Reflection effects]]<br />
###[[Luster]]<br />
###[[Sheen]]<br />
####[[Sheen#Chatoyancy | Chatoyancy]]<br />
####[[Sheen#Asterism | Asterism]]<br />
####[[Sheen#Iridescence | Iridescence]]<br />
###[[Brilliance | Brilliance (Total Internal Reflection)]]<br />
##[[Polarization]]<br />
##[[Pleochroism]]<br />
##[[Color]]<br />
###[[Causes of color]]<br />
##[[Refraction]]<br />
###[[Double Refraction]]<br />
##[[Dispersion]]<br />
##[[Diffraction]]<br />
##[[Interference]]<br />
##[[Luminescence]]<br />
###[[Luminescence#Fluorescence | Fluorescence]]<br />
###[[Luminescence#Phosphorescence | Phosphorescence]]<br />
###[[Luminescence#Tenebrescence | Tenebrescence]]<br />
###[[Luminescence#Triboluminescence | Triboluminescence]]<br />
#[[Hardness]]<br />
#[[Specific Gravity]]<br />
#[[Math| Basic math for gemology]]<br />
##[[Math#Cross-multiplication | Cross-multiplication]]<br />
##[[Math#Sine.2C_cosine_and_tangent | Sine, cosine and tangent]]<br />
##[[Math#Degrees.2C_minutes_and_seconds | Degrees, minutes and seconds]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
#[[Equipment used to identify gemstones]]<br />
##[[10x Loupe]]<br />
##[[Spectroscope]]<br />
##[[Refractometer]]<br />
##[[Polariscope]]<br />
##[[Dichroscope]]<br />
##[[Immersion Cell]]<br />
##[[Color Filters]]<br />
##[[Microscope]]<br />
##[[Hydrostatic Balance]]<br />
##[[Heavy Liquids]]<br />
##[[Hardness#Hardness_pencils|Hardness pencils]]<br />
#[[Inclusions]]<br />
#[[Synthetic gemstones]]<br />
#[[Visual Optics]]<br />
##[[The Hodgkinson Method]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
*[[Alphabetic list by gemstone name]]<br />
#[[Diamond]]<br />
#[[Corundum]]<br />
##[[Ruby]]<br />
##[[Sapphire]]<br />
#[[Beryl]]<br />
##[[Aquamarine]]<br />
##[[Bixbite]]<br />
##[[Emerald]]<br />
###[[Vanadium Beryl]]<br />
##[[Goshenite]]<br />
##[[Green Beryl]]<br />
##[[Heliodor]]<br />
##[[Maxixe]]<br />
##[[Morganite]]<br />
##[[Riesling]]<br />
##[[True Blue]]<br />
##[[Pezzottaite]] (Beryl Group)<br />
#[[Quartz]]<br />
##[[Amethyst]]<br />
##[[Ametrine]]<br />
##[[Citrine]]<br />
##[[Prasiolite]]<br />
##[[Rock Crystal]]<br />
##[[Rose Quartz]]<br />
##[[Smokey Quartz]]<br />
#[[Quartz - Microcrystalline]]<br />
##[[Chalcedony]]<br />
###[[Agate]]<br />
###[[Bloodstone]]<br />
###[[Carnelian]]<br />
###[[Chrysoprase]]<br />
###[[Jasper]]<br />
###[[Onyx]]<br />
###[[Sard]]<br />
###[[Sardonyx]]<br />
###[[Tigereye]]<br />
#[[Zoisite]]<br />
##[[Tanzanite]]<br />
##[[Thulite]]<br />
#[[Garnet]]<br />
##[[Almandine]]<br />
##[[Andradite]]<br />
###[[Andradite#Demantoid|Demantoid]]<br />
##[[Grossular]]<br />
###[[Grossular#Chrome_grossular|Chrome grossular]]<br />
###[[Grossular#Hessonite|Hessonite]]<br />
###[[Grossular#Hydrogrossular |Hydrogrossular]]<br />
###[[Grossular#Mali|Mali]]<br />
###[[Grossular#Tsavorite|Tsavorite]]<br />
##[[Pyrope]]<br />
##[[Spessartite]]<br />
##[[Uvarovite]]<br />
#[[Diopside]]<br />
##[[Chrome Diopside]]<br />
##[[Tashmarine]]&trade;<br />
#[[Feldspar]]<br />
##[[Amazonite]]<br />
##[[Andesine]]<br />
##[[Labradorite]]<br />
##[[Moonstone]]<br />
##[[Spectrolite]]<br />
##[[Sunstone]]<br />
#[[Spodumene]]<br />
##[[Hiddenite]]<br />
##[[Kunzite]]<br />
#[[Chrysoberyl]]<br />
##[[Alexandrite]]<br />
#[[Spinel]]<br />
#[[Tourmaline]]<br />
##[[Chrome]]<br />
##[[Indicolite]]<br />
##[[Liddicoatite]]<br />
##[[Paraiba type]]<br />
##[[Rubellite]]<br />
#[[Amber]]<br />
#[[Ammolite]]<br />
#[[Anatase]]<br />
#[[Andalusite]]<br />
#[[Apatite]]<br />
#[[Benitoite]]<br />
#[[Bowenite]]<br />
#[[Charoite]]<br />
#[[Chrysocolla]]<br />
#[[Coral]]<br />
#[[Danburite]]<br />
#[[Datolite]]<br />
#[[Dioptase]]<br />
#[[Enstatite]]<br />
#[[Fluorite]]<br />
#[[Glass]]<br />
##[[Goldstone]]<br />
#[[Hauyne]]<br />
#[[Iolite]]<br />
#[[Jade]]<br />
##[[Jadeite]]<br />
##[[Nephrite]]<br />
#[[Konerupine]]<br />
#[[Lapis Lazuli]]<br />
#[[Larimar]]<br />
#[[Maw-sit-sit]]<br />
#[[Opal]]<br />
##[[Black Opal]]<br />
##[[Blue Peruvian Opal]]<br />
##[[Boulder Opal]]<br />
##[[Fire Opal]]<br />
#[[Pearl]]<br />
##[[Salt water]]<br />
###[[Akoya]]<br />
###[[Tahitian]]<br />
###[[South Sea]]<br />
###[[Mabé]]<br />
###[[Conch Pearl]]<br />
###[[Melo Pearl]]<br />
###[[Quahog]]<br />
##[[Freshwater Pearl]]<br />
###[[Kasumiga pearls]]<br />
###[[Chinese freshwater pearls]]<br />
#[[Peridot]]<br />
#[[Poudretteite]]<br />
#[[Scapolite]]<br />
#[[Sodalite]]<br />
##[[Hackmanite]]<br />
#[[Sphalerite]]<br />
#[[Sphene]]<br />
#[[Topaz]]<br />
#[[Turquoise]]<br />
#[[Vesuvianite]]<br />
#[[Zincite]]<br />
#[[Zircon]]<br />
<br />
<br />
<br />
|}</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Table_Of_Contents&diff=5030Table Of Contents2007-01-09T03:04:57Z<p>Russell: </p>
<hr />
<div>In this TOC (Table Of Content) you will find pages that have been published presented in blue and pages that yet need to be written presented in red. For better navigation, we list the pages in 3 categories:<br />
#Theory - Basic and in-depth mechanisms involved in gemology<br />
#Practical - Descriptions of instruments, techniques and other practical discussions<br />
#Gemstones - Information about the gemstone at hand<br />
<br />
For the neophyte it is best to start in that order as some words and principles introduced in the theory pages will need to be understood first. At the very least, one should learn the theory in the "basic" sections of the pages.<br /><br />
Although gemology is not rocket science, some science and math is involved. We don't believe in the dumbing-down of gemology, so you should be ready and willing to expand your horizons. If you find any of the technical concepts difficult to visualize or grasp, go to the forum (the link is above) and ask. We will help you with it, and at the same time you will help this project become more complete for those who come after you. <br />
<br />
We never said it was going to be easy. But it's a heck of an interesting ride.<br />
<br />
<br />
{| {{toctable}} width="100%"<br />
<br />
!Theory <br />
!Practical<br />
!Gemstones<br />
<br />
|-<br />
<br />
|style="padding-right:5px" valign="top"|<br />
:'''Content'''<br />
#[[Introduction to Gemology]]<br />
##[[Introduction_to_Gemology#Education|Education]]<br />
##[[An Historical Look at our Obsession with Gems]]<br />
##[[Glossary of Terms]]<br />
#[[Origins of minerals]]<br />
##[[Origins_of_minerals#Igneous_.28Magmatic.29_rocks|Igneous rocks]]<br />
##[[Origins_of_minerals#Sedimentary_rocks|Sedimentary rocks]]<br />
##[[Origins_of_minerals#Metamorphic_rocks|Metamorphic rocks]]<br />
#[[The Chemistry of Gemstones]]<br />
##[[Isomorphous replacement]]<br />
##[[The Chemical Classification of Gems & Minerals]]<br />
#[[Crystallography]]<br />
##[[Crystal Systems]]<br />
##[[Form]]<br />
##[[Habit]]<br />
##[[Symmetry]]<br />
##[[Twinning]]<br />
#[[Cleavage]]<br />
#[[Cleavage#Parting|Parting]]<br />
#[[Cleavage#Fracture|Fracture]]<br />
#[[Optical properties of gemstones]]<br />
##[[Nature of light]]<br />
###[[Nature_of_light#The_electromagnetic_wave_theory |The electromagnetic wave theory]]<br />
###[[Nature_of_light#The_quantum_theory |The quantum theory]]<br />
###[[Nature_of_light#The_electromagnetic_spectrum |The electromagnetic spectrum]]<br />
##[[Reflection effects]]<br />
###[[Luster]]<br />
###[[Sheen]]<br />
####[[Sheen#Chatoyancy | Chatoyancy]]<br />
####[[Sheen#Asterism | Asterism]]<br />
####[[Sheen#Iridescence | Iridescence]]<br />
###[[Brilliance | Brilliance (Total Internal Reflection)]]<br />
##[[Polarization]]<br />
##[[Pleochroism]]<br />
##[[Color]]<br />
###[[Causes of color]]<br />
##[[Refraction]]<br />
###[[Double Refraction]]<br />
##[[Dispersion]]<br />
##[[Diffraction]]<br />
##[[Interference]]<br />
##[[Luminescence]]<br />
###[[Luminescence#Fluorescence | Fluorescence]]<br />
###[[Luminescence#Phosphorescence | Phosphorescence]]<br />
###[[Luminescence#Tenebrescence | Tenebrescence]]<br />
###[[Luminescence#Triboluminescence | Triboluminescence]]<br />
#[[Hardness]]<br />
#[[Specific Gravity]]<br />
#[[Math| Basic math for gemology]]<br />
##[[Math#Cross-multiplication | Cross-multiplication]]<br />
##[[Math#Sine.2C_cosine_and_tangent | Sine, cosine and tangent]]<br />
##[[Math#Degrees.2C_minutes_and_seconds | Degrees, minutes and seconds]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
#[[Equipment used to identify gemstones]]<br />
##[[10x Loupe]]<br />
##[[Spectroscope]]<br />
##[[Refractometer]]<br />
##[[Polariscope]]<br />
##[[Dichroscope]]<br />
##[[Immersion Cell]]<br />
##[[Color Filters]]<br />
##[[Microscope]]<br />
##[[Hydrostatic Balance]]<br />
##[[Heavy Liquids]]<br />
##[[Hardness#Hardness_pencils|Hardness pencils]]<br />
#[[Inclusions]]<br />
#[[Synthetic gemstones]]<br />
#[[Visual Optics]]<br />
##[[The Hodgkinson Method]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
*[[Alphabetic list by gemstone name]]<br />
#[[Diamond]]<br />
#[[Corundum]]<br />
##[[Ruby]]<br />
##[[Sapphire]]<br />
#[[Beryl]]<br />
##[[Aquamarine]]<br />
##[[Bixbite]]<br />
##[[Emerald]]<br />
###[[Vanadium Beryl]]<br />
##[[Goshenite]]<br />
##[[Green Beryl]]<br />
##[[Heliodor]]<br />
##[[Maxixe]]<br />
##[[Morganite]]<br />
##[[Riesling]]<br />
##[[True Blue]]<br />
##[[Pezzottaite]] (Beryl Group)<br />
#[[Quartz]]<br />
##[[Amethyst]]<br />
##[[Ametrine]]<br />
##[[Citrine]]<br />
##[[Prasiolite]]<br />
##[[Rock Crystal]]<br />
##[[Rose Quartz]]<br />
##[[Smokey Quartz]]<br />
#[[Quartz - Microcrystalline]]<br />
##[[Chalcedony]]<br />
###[[Agate]]<br />
###[[Bloodstone]]<br />
###[[Carnelian]]<br />
###[[Chrysoprase]]<br />
###[[Jasper]]<br />
###[[Onyx]]<br />
###[[Sard]]<br />
###[[Sardonyx]]<br />
###[[Tigereye]]<br />
#[[Zoisite]]<br />
##[[Tanzanite]]<br />
##[[Thulite]]<br />
#[[Garnet]]<br />
##[[Almandine]]<br />
##[[Andradite]]<br />
###[[Andradite#Demantoid|Demantoid]]<br />
##[[Grossular]]<br />
###[[Grossular#Chrome_grossular|Chrome grossular]]<br />
###[[Grossular#Hessonite|Hessonite]]<br />
###[[Grossular#Hydrogrossular |Hydrogrossular]]<br />
###[[Grossular#Mali|Mali]]<br />
###[[Grossular#Tsavorite|Tsavorite]]<br />
##[[Pyrope]]<br />
##[[Spessartite]]<br />
##[[Uvarovite]]<br />
#[[Diopside]]<br />
##[[Chrome Diopside]]<br />
##[[Tashmarine]]&trade;<br />
#[[Feldspar]]<br />
##[[Amazonite]]<br />
##[[Andesine]]<br />
##[[Labradorite]]<br />
##[[Moonstone]]<br />
##[[Spectrolite]]<br />
##[[Sunstone]]<br />
#[[Spodumene]]<br />
##[[Hiddenite]]<br />
##[[Kunzite]]<br />
#[[Chrysoberyl]]<br />
##[[Alexandrite]]<br />
#[[Spinel]]<br />
#[[Tourmaline]]<br />
##[[Chrome]]<br />
##[[Indicolite]]<br />
##[[Liddicoatite]]<br />
##[[Paraiba type]]<br />
##[[Rubellite]]<br />
#[[Amber]]<br />
#[[Ammolite]]<br />
#[[Anatase]]<br />
#[[Andalusite]]<br />
#[[Apatite]]<br />
#[[Benitoite]]<br />
#[[Bowenite]]<br />
#[[Charoite]]<br />
#[[Chrysocolla]]<br />
#[[Coral]]<br />
#[[Danburite]]<br />
#[[Datolite]]<br />
#[[Dioptase]]<br />
#[[Enstatite]]<br />
#[[Fluorite]]<br />
#[[Glass]]<br />
##[[Goldstone]]<br />
#[[Hauyne]]<br />
#[[Iolite]]<br />
#[[Jade]]<br />
##[[Jadeite]]<br />
##[[Nephrite]]<br />
#[[Konerupine]]<br />
#[[Lapis Lazuli]]<br />
#[[Larimar]]<br />
#[[Maw-sit-sit]]<br />
#[[Opal]]<br />
##[[Black Opal]]<br />
##[[Blue Peruvian Opal]]<br />
##[[Boulder Opal]]<br />
##[[Fire Opal]]<br />
#[[Pearl]]<br />
##[[Salt water]]<br />
###[[Akoya]]<br />
###[[Tahitian]]<br />
###[[South Sea]]<br />
###[[Mabé]]<br />
###[[Conch Pearl]]<br />
###[[Melo Pearl]]<br />
###[[Quahog]]<br />
##[[Freshwater Pearl]]<br />
###[[Kasumiga pearls]]<br />
###[[Chinese freshwater pearls]]<br />
#[[Peridot]]<br />
#[[Poudretteite]]<br />
#[[Scapolite]]<br />
#[[Sodalite]]<br />
##[[Hackmanite]]<br />
#[[Sphalerite]]<br />
#[[Sphene]]<br />
#[[Topaz]]<br />
#[[Turquoise]]<br />
#[[Vesuvianite]]<br />
#[[Zircon]]<br />
<br />
<br />
<br />
|}</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Table_Of_Contents&diff=5029Table Of Contents2007-01-09T03:02:38Z<p>Russell: </p>
<hr />
<div>In this TOC (Table Of Content) you will find pages that have been published presented in blue and pages that yet need to be written presented in red. For better navigation, we list the pages in 3 categories:<br />
#Theory - Basic and in-depth mechanisms involved in gemology<br />
#Practical - Descriptions of instruments, techniques and other practical discussions<br />
#Gemstones - Information about the gemstone at hand<br />
<br />
For the neophyte it is best to start in that order as some words and principles introduced in the theory pages will need to be understood first. At the very least, one should learn the theory in the "basic" sections of the pages.<br /><br />
Although gemology is not rocket science, some science and math is involved. We don't believe in the dumbing-down of gemology, so you should be ready and willing to expand your horizons. If you find any of the technical concepts difficult to visualize or grasp, go to the forum (the link is above) and ask. We will help you with it, and at the same time you will help this project become more complete for those who come after you. <br />
<br />
We never said it was going to be easy. But it's a heck of an interesting ride.<br />
<br />
<br />
{| {{toctable}} width="100%"<br />
<br />
!Theory <br />
!Practical<br />
!Gemstones<br />
<br />
|-<br />
<br />
|style="padding-right:5px" valign="top"|<br />
:'''Content'''<br />
#[[Introduction to Gemology]]<br />
##[[Introduction_to_Gemology#Education|Education]]<br />
##[[An Historical Look at our Obsession with Gems]]<br />
##[[Glossary of Terms]]<br />
#[[Origins of minerals]]<br />
##[[Origins_of_minerals#Igneous_.28Magmatic.29_rocks|Igneous rocks]]<br />
##[[Origins_of_minerals#Sedimentary_rocks|Sedimentary rocks]]<br />
##[[Origins_of_minerals#Metamorphic_rocks|Metamorphic rocks]]<br />
#[[The Chemistry of Gemstones]]<br />
##[[Isomorphous replacement]]<br />
##[[The Chemical Classification of Gems & Minerals]]<br />
#[[Crystallography]]<br />
##[[Crystal Systems]]<br />
##[[Form]]<br />
##[[Habit]]<br />
##[[Symmetry]]<br />
##[[Twinning]]<br />
#[[Cleavage]]<br />
#[[Cleavage#Parting|Parting]]<br />
#[[Cleavage#Fracture|Fracture]]<br />
#[[Optical properties of gemstones]]<br />
##[[Nature of light]]<br />
###[[Nature_of_light#The_electromagnetic_wave_theory |The electromagnetic wave theory]]<br />
###[[Nature_of_light#The_quantum_theory |The quantum theory]]<br />
###[[Nature_of_light#The_electromagnetic_spectrum |The electromagnetic spectrum]]<br />
##[[Reflection effects]]<br />
###[[Luster]]<br />
###[[Sheen]]<br />
####[[Sheen#Chatoyancy | Chatoyancy]]<br />
####[[Sheen#Asterism | Asterism]]<br />
####[[Sheen#Iridescence | Iridescence]]<br />
###[[Brilliance | Brilliance (Total Internal Reflection)]]<br />
##[[Polarization]]<br />
##[[Pleochroism]]<br />
##[[Color]]<br />
###[[Causes of color]]<br />
##[[Refraction]]<br />
###[[Double Refraction]]<br />
##[[Dispersion]]<br />
##[[Diffraction]]<br />
##[[Interference]]<br />
##[[Luminescence]]<br />
###[[Luminescence#Fluorescence | Fluorescence]]<br />
###[[Luminescence#Phosphorescence | Phosphorescence]]<br />
###[[Luminescence#Tenebrescence | Tenebrescence]]<br />
###[[Luminescence#Triboluminescence | Triboluminescence]]<br />
#[[Hardness]]<br />
#[[Specific Gravity]]<br />
#[[Math| Basic math for gemology]]<br />
##[[Math#Cross-multiplication | Cross-multiplication]]<br />
##[[Math#Sine.2C_cosine_and_tangent | Sine, cosine and tangent]]<br />
##[[Math#Degrees.2C_minutes_and_seconds | Degrees, minutes and seconds]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
#[[Equipment used to identify gemstones]]<br />
##[[10x Loupe]]<br />
##[[Spectroscope]]<br />
##[[Refractometer]]<br />
##[[Polariscope]]<br />
##[[Dichroscope]]<br />
##[[Immersion Cell]]<br />
##[[Color Filters]]<br />
##[[Microscope]]<br />
##[[Hydrostatic Balance]]<br />
##[[Heavy Liquids]]<br />
##[[Hardness#Hardness_pencils|Hardness pencils]]<br />
#[[Inclusions]]<br />
#[[Synthetic gemstones]]<br />
#[[Visual Optics]]<br />
##[[The Hodgkinson Method]]<br />
<br />
| style="padding-right:5px" valign=top|<br />
:'''Content'''<br />
*[[Alphabetic list by gemstone name]]<br />
#[[Diamond]]<br />
#[[Corundum]]<br />
##[[Ruby]]<br />
##[[Sapphire]]<br />
#[[Beryl]]<br />
##[[Aquamarine]]<br />
##[[Bixbite]]<br />
##[[Emerald]]<br />
###[[Vanadium Beryl]]<br />
##[[Goshenite]]<br />
##[[Green Beryl]]<br />
##[[Heliodor]]<br />
##[[Maxixe]]<br />
##[[Morganite]]<br />
##[[Riesling]]<br />
##[[True Blue]]<br />
##[[Pezzottaite]] (Beryl Group)<br />
#[[Quartz]]<br />
##[[Amethyst]]<br />
##[[Ametrine]]<br />
##[[Citrine]]<br />
##[[Prasiolite]]<br />
##[[Rock Crystal]]<br />
##[[Rose Quartz]]<br />
##[[Smokey Quartz]]<br />
#[[Quartz - Microcrystalline]]<br />
##[[Chalcedony]]<br />
###[[Agate]]<br />
###[[Bloodstone]]<br />
###[[Carnelian]]<br />
###[[Chrysoprase]]<br />
###[[Jasper]]<br />
###[[Onyx]]<br />
###[[Sard]]<br />
###[[Sardonyx]]<br />
###[[Tigereye]]<br />
#[[Zoisite]]<br />
##[[Tanzanite]]<br />
##[[Thulite]]<br />
#[[Garnet]]<br />
##[[Almandine]]<br />
##[[Andradite]]<br />
###[[Andradite#Demantoid|Demantoid]]<br />
##[[Grossular]]<br />
###[[Grossular#Chrome_grossular|Chrome grossular]]<br />
###[[Grossular#Hessonite|Hessonite]]<br />
###[[Grossular#Hydrogrossular |Hydrogrossular]]<br />
###[[Grossular#Mali|Mali]]<br />
###[[Grossular#Tsavorite|Tsavorite]]<br />
##[[Pyrope]]<br />
##[[Spessartite]]<br />
##[[Uvarovite]]<br />
#[[Diopside]]<br />
##[[Chrome Diopside]]<br />
##[[Tashmarine]]&trade;<br />
#[[Feldspar]]<br />
##[[Amazonite]]<br />
##[[Andesine]]<br />
##[[Labradorite]]<br />
##[[Moonstone]]<br />
##[[Spectrolite]]<br />
##[[Sunstone]]<br />
#[[Spodumene]]<br />
##[[Hiddenite]]<br />
##[[Kunzite]]<br />
#[[Chrysoberyl]]<br />
##[[Alexandrite]]<br />
#[[Spinel]]<br />
#[[Tourmaline]]<br />
##[[Chrome]]<br />
##[[Indicolite]]<br />
##[[Liddicoatite]]<br />
##[[Paraiba type]]<br />
##[[Rubellite]]<br />
#[[Amber]]<br />
#[[Ammolite]]<br />
#[[Anatase]]<br />
#[[Andalusite]]<br />
#[[Apatite]]<br />
#[[Benitoite]]<br />
#[[Bowenite]]<br />
#[[Charoite]]<br />
#[[Chrysocolla]]<br />
#[[Coral]]<br />
#[[Danburite]]<br />
#[[Datolite]]<br />
#[[Dioptase]]<br />
#[[Enstatite]]<br />
#[[Fluorite]]<br />
#[[Glass]]<br />
##[[Goldstone]]<br />
#[[Hauyne]]<br />
#[[Iolite]]<br />
#[[Jade]]<br />
##[[Jadeite]]<br />
##[[Nephrite]]<br />
#[[Konerupine]]<br />
#[[Lapis Lazuli]]<br />
#[[Larimar]]<br />
#[[Maw-sit-sit]]<br />
#[[Opal]]<br />
##[[Black Opal]]<br />
##[[Blue Peruvian Opal]]<br />
##[[Boulder Opal]]<br />
##[[Fire Opal]]<br />
#[[Pearl]]<br />
##[[Salt water]]<br />
###[[Akoya]]<br />
###[[Tahitian]]<br />
###[[South Sea]]<br />
###[[Mabé]]<br />
###[[Conch Pearl]]<br />
###[[Melo Pearl]]<br />
###[[Quahog]]<br />
##[[Freshwater Pearl]]<br />
###[[Kasumiga pearls]]<br />
###[[Chinese freshwater pearls]]<br />
#[[Peridot]]<br />
#[[Poudretteite]]<br />
#[[Scapolite]]<br />
#[[Sodalite]]<br />
##[[Hackmanite]]<br />
#[[Sphalerite]]<br />
#[[Sphene]]<br />
#[[Topaz]]<br />
#[[Turquoise]]<br />
#[[Vesuvianite]]<br />
#[[Zincite]]<br />
#[[Zircon]]<br />
<br />
<br />
<br />
|}</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Datolite&diff=5002Datolite2007-01-07T23:27:59Z<p>Russell: /* Chemical composition */</p>
<hr />
<div>{{datolite}}<br />
<br />
[[image:datolite1.jpg|left|200px|thumb|Datolite from the Caledonia Mine, Mass City, Michigan]]<br />
<br clear="left" /><br />
Datolite was named 1806 by Professor Jens Esmark from the Greek “to divide,” referring to the granular structure of the first specimens studied from Arendal, Norway.<br />
<br />
==Chemical composition==<br />
Calcium boron silicate hydroxide, CaBSiO4(OH) with minor to trace amounts of iron, manganese, and aluminum.<br />
<br />
==Diagnostics==<br />
<br />
===Color===<br />
<br />
Crystals are colorless to white, often with a pale green or greenish yellow tint. Massive datolite is translucent to opaque grayish, reddish, pink, brown or yellow.<br />
<br />
===Refractive index===<br />
<br />
Optical nature and sign: biaxial negative<br /><br />
Refractive Index: n<sub>α</sub> = 1.622 – 1.626 n<sub>β</sub> = 1.649 – 1.654 n<sub>γ</sub> = 1.666 – 1.670<br />
<br />
===Magnification===<br />
<br />
Massive datolite from Michigan cut en cabochon sometimes exhibits microscopic inclusions of native copper. The copper has sometimes oxidized to give the rough a copper-green color.<br />
<br />
==Occurence==<br />
<br />
Small quantities of greenish yellow to colorless datolite faceting rough have been produced at Dal'negorsk (Dalnegorsk), Primorskiy Kray, Russia. In addition to faceting rough, there was a largely unsuccessful attempt about 2002 to introduce a skarn rock composed of wollastonite and datolite to the US lapidary market; the material is marked by alternating bands light and dark olive-green bands and swirls. The skarn was apparently also produced in Primorskiy Kray (Dalnegorsk?). Compact, porcelain-like masses of datolite, some as large as 30cm in diameter and of a pleasing brown, red, yellow, malachite-green, white or grey color,, have been recovered since the mid-19th century from dozens of mines in Houghton, Keweenaw, and Ontonagen counties in Michigan’s famed “Copper Peninsula.” Rough is still being recovered by reworking abandoned mine dumps as well as scuba diving off the coastline.<br />
<br />
==Sources==<br />
*Rosemeyer, T. (2003) The occurrence of porcelaneous datolite in michigan's lake superior copper district Part I: Northern Keweenaw County and Isle Royale National Park Rocks & Minerals, Vol. 78 No. 3 pp. 170-88<br />
<br />
*Rosemeyer, T. (2005) The occurrence of porcelaneous datolite in Michigan's Lake Superior Copper District: part 2: Southern Keweenaw, Houghton, and Ontonagon Counties, Michigan. Rocks & Minerals, Rocks & Minerals Vol 80 No. 3 pp154-177<br />
<br />
==External links==<br />
* [http://www.minsocam.org/MSA/collectors_corner/vft/mi4c.htm Keneewa Michigan field trip]<br />
* [http://www.minsocam.org/MSA/collectors_corner/vft/mi4c1.htm Lapidary additional]</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Benitoite&diff=4984Benitoite2007-01-06T02:16:24Z<p>Russell: </p>
<hr />
<div>{{benitoite}}<br />
Beniotite is a very rare mineral that was discovered in 1907 in San Benito County in California. It has never been found elsewhere. It was originally mistaken for [[[[sapphire]].]] Benitoite is very highly dispersive (the ability to take white light and disperse it into various components of the spectrum). Benitoite is associated with other rare minerals such as black-red neptunite, snow white natrolite and brown-yellow joaquinite. Since the only source of this rare combination occurs at San Benito County, California, it has been designated the California state gemstone. Crystals, and cut stones, tend to be small and quite expensive!</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Quahog&diff=4982Quahog2007-01-06T00:37:46Z<p>Russell: </p>
<hr />
<div>= '''Quahog''' =<br />
<br />
<br />
<br />
Also known as “The Northern Quahog” or “Hard Clam,” this marine bivalve is found along the eastern seaboard of the United States from Maine to Florida, and is especially common from Massachusetts to New Jersey<br />
<br />
Its name is pronounced KO-hog, not “kwag” or “KWA-hog”, and derives from the Narragansett Indians’ name for the clam, "poquauhock.” The interior lip of the clam’s shell is commonly colored light to royal purple to dark purple in stark contrast to the remainder of the mostly-white shell. This segment of the shell was ground into purple beads by Native Americans living along the eastern seaboard of the United States to form “wampum,” an important item of barter among Native Americans. Hence this species of bivalve carries the scientific name of ''Mercenaria mercenaria'', derived from the Latin word for “money”. (Older references may cite this bivalve as ''Venus mercenaria'', but it was reassigned by biologists.)<br />
<br />
<br />
=== Quahog “Pearls” ===<br />
<br />
The Quahog sometimes produces concretions of shell material which range in shape from flattened disks (aptly described as “shaped like an M&M candy”) to spheres, and in color from white to pale purple to a deep purple-black. '''These concretions lack the lustrous nacreous layers that are characteristic of gem pearls''' derived from oysters and are composed of layers of aragonite crystals interspersed with organic material.</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Quahog&diff=4981Quahog2007-01-06T00:35:59Z<p>Russell: </p>
<hr />
<div>= '''Quahog''' =<br />
<br />
<br />
<br />
Also known as “The Northern Quahog” or “Hard Clam,” this marine bivalve is found along the eastern seaboard of the United States from Maine to Florida, and is especially common from Massachusetts to New Jersey<br />
<br />
Its name is pronounced KO-hog, not “kwag” or “KWA-hog”, and derives from the Narragansett Indians’ name for the clam, "poquauhock.” The interior lip of the clam’s shell is commonly colored light to royal purple to dark purple in stark contrast to the remainder of the mostly-white shell. This segment of the shell was ground into purple beads by Native Americans living along the eastern seaboard of the United States to form “wampum,” an important item of barter among Native Americans. Hence this species of bivalve carries the scientific name of ''Mercenaria mercenaria'', derived from the Latin word for “money”. (Older references may cite this bivalve as ''Venus mercenaria'', but it was reassigned by biologists.)<br />
<br />
<br />
=== Quahog “Pearls” ===<br />
<br />
The Quahog sometimes produces concretions of shell material which range in shape from flattened disks (aptly described as “shaped like an M&M candy”) to spheres, and in color from white to pale purple to a deep purple-black. '''These concretions lack the lustrous nacreous layers that are characteristic of gem pearls''' derived from oysters.</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Quahog&diff=4980Quahog2007-01-06T00:35:14Z<p>Russell: </p>
<hr />
<div>= '''Quahog''' =<br />
<br />
<br />
<br />
Also known as “The Northern Quahog” or “Hard Clam,” this marine bivalve is found along the eastern seaboard of the United States from Maine to Florida, and is especially common from Massachusetts to New Jersey<br />
<br />
Its name is pronounced KO-hog, not “kwag” or “KWA-hog”, and derives from the Narragansett Indians’ name for the clam, "poquauhock.” The interior lip of the clam’s shell is commonly colored light to royal purple to dark purple in stark contrast to the remainder of the mostly-white shell. This segment of the shell was ground into purple beads by Native Americans living along the eastern seaboard of the United States to form “wampum,” an important item of barter among Native Americans. Hence this species of bivalve carries the scientific name of ''Mercenaria mercenaria'', derived from the Latin word for “money”. (Older references may cite this bivalve as ''Venus mercenaria'', but it was reassigned by biologists.)<br />
<br />
<br />
=== Quahog “Pearls” ===<br />
<br />
The Quahog sometimes produces concretions of shell material which range in shape from flattened disks (aptly described as “shaped like an M&M candy”) to spheres, and in color from white to pale purple to a deep purple-back. '''These concretions lack the lustrous nacreous layers that are characteristic of gem pearls''' derived from oysters.</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Quahog&diff=4979Quahog2007-01-06T00:33:32Z<p>Russell: </p>
<hr />
<div>= '''Quahog''' =<br />
<br />
<br />
<br />
Also known as “The Northern Quahog” or “Hard Clam,” this marine bivalve is found along the eastern seaboard of the United States from Maine to Florida, and is especially common from Massachusetts to New Jersey<br />
<br />
Its name is pronounced KO-hog, not “kwag” or “KWA-hog”, and derives from the Narragansett Indians’ name for the clam, "poquauhock.” The interior lip of the clam’s shell is commonly colored royal purple in stark contrast to the remainder of the mostly-white shell. This segment of the shell was ground into purple beads by Native Americans living along the eastern seaboard of the United States to form “wampum,” an important item of barter among Native Americans. Hence this species of bivalve carries the scientific name of Mercenaria mercenaria, derived from the Latin word for “money”. (Older references may cite this bivalve as Venus mercenaria, but it was reassigned by biologists.)<br />
<br />
<br />
=== Quahog “Pearls” ===<br />
<br />
The Quahog sometimes produces concretions of shell material which range in shape from flattened disks (aptly described as “shaped like an M&M candy”) to spheres, and in color from white to pale purple to a deep purple-back. '''These concretions lack the lustrous nacreous layers that are characteristic of gem pearls''' derived from oysters.</div>Russellhttp://www.gemologyproject.com/wiki/index.php?title=Quahog&diff=4978Quahog2007-01-06T00:31:22Z<p>Russell: </p>
<hr />
<div><br />
== '''Quahog''' ==<br />
<br />
<br />
<br />
Also known as “The Northern Quahog” or “Hard Clam,” this marine bivalve is found along the eastern seaboard of the United States from Maine to Florida, and is especially common from Massachusetts to New Jersey<br />
<br />
Its name is pronounced KO-hog, not “kwag” or “KWA-hog”, and derives from the Narragansett Indians’ name for the clam, "poquauhock.” The interior lip of the clam’s shell is commonly colored royal purple in stark contrast to the remainder of the mostly-white shell. This segment of the shell was ground into purple beads by Native Americans living along the eastern seaboard of the United States to form “wampum,” an important item of barter among Native Americans. Hence this species of bivalve carries the scientific name of Mercenaria mercenaria, derived from the Latin word for “money”. (Older references may cite this bivalve as Venus mercenaria, but it was reassigned by biologists.)<br />
<br />
'''[[Quahog “Pearls”]]'''<br />
<br />
The Quahog sometimes produces concretions of shell material which range in shape from flattened disks (aptly described as “shaped like an M&M candy”) to spheres, and in color from white to pale purple to a deep purple-back. '''These concretions lack the lustrous nacreous layers that are characteristic of gem pearls''' derived from oysters.</div>Russell