Difference between revisions of "Nephrite"

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(Sources consulted)
(G&G Articles on Jade 1934-1980)
 
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/fall-1979.pdf Fall 1979, <b>Clarification of Composition of Maw Sit Sit</b>, p. 217, 2p.]
 
</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/fall-1979.pdf Fall 1979, <b>Clarification of Composition of Maw Sit Sit</b>, p. 217, 2p.]
 
</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/summer-1980.pdf Summer 1980, <b>Australia Likely To Be Major Supplier of Jade</b>, by J. Stone, p. 331, 1p.]
 
</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/summer-1980.pdf Summer 1980, <b>Australia Likely To Be Major Supplier of Jade</b>, by J. Stone, p. 331, 1p.]
</li></ul>
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</li>
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<li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/summer-1943.pdf Summer 1943, <b>So-called "Mexican jade" is calcite</b>, p. 87, 1p.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/winter-1955.pdf Winter 1955,<b> Cat's-eye nephrite</b>, p. 238, 1p.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/spring-1958.pdf Spring 1958, <b>Jadeite triplets</b>, p. 134, 3pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/winter-1961.pdf Winter 1961, <b>Jadeite "Yunnan Jade" from Burma</b> (showing absorption spectrum), p. 242, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/spring-1963.pdf Spring 1962, <b>Rare gray-blue jadeite</b>, p. 283, 1p.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/winter-1963.pdf Winter 1963, <b>Faded dyed jadeite</b>, p. 100, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/summer-1965.pdf Summer 1964, <b>Stable color in dyed jadeite</b>, p. 181, 1p.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/winter-1965.pdf Winter 1965, <b>Dyed nephrite first seen at the GIA</b>, p. 363, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/winter-1965.pdf Winter 1965, <b>A new type of jadeite triplet (two pieces of jadeite, green coloring in center)</b>, p. 369, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/winter-1967.pdf Winter 1967, <b>Dyed jadeite</b>, p. 245, 1p.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/summer-1969.pdf Summer 1969, <b>Glass jade imitation</b>, p. 58, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/winter-1970.pdf Winter 1970, <b>Glass-like jade imitation</b>, p. 249, 3pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/summer-1971.pdf Summer 1971, <b>Dyed lavender jadeite</b>, p. 323, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/summer-1972.pdf Summer 1972, <b>Jade substitute (glass)</b>, p. 44, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/summer-1972.pdf Summer 1972, <b>Jade-like minerals</b>, p. 50, 3pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/fall-1972.pdf Fall 1972, <b>Distinguishing burial jade from burned jade not yet possible</b>, p. 83, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/fall-1972.pdf Fall 1972, <b>Paraffin-treated jade</b>, p. 84, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/fall-1972.pdf Fall 1972, <b>Blue jade-like material (tremolite)</b>, p. 91, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/fall-1972.pdf Fall 1972, <b>A cat's-eye yellow jadeite</b>, p. 93, 1p.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/winter-1972.pdf Winter 1972, <b>Testing dyed antique replicas of j</b>ade, p. 112, 1p.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/winter-1972.pdf Winter 1972, <b>Jade cat's-eye (?),</b> p. 113, 1p.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/spring-1973.pdf Spring 1973, <b>Jade imitations in devitrified fibrous glass (meta jade, Imori stone)</b>, p. 134, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/summer-1973.pdf Summer 1973, <b>Durability of jadeite vs. nephrite</b>, p. 175, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/fall-1973.pdf Fall 1973, <b>Treated lavender jadeite</b>, p. 214, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/fall-1974.pdf Fall 1974, <b>Unevenly dyed jadeite</b>, p. 350, 1p.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/spring-1975.pdf Spring 1975, <b>A "meta jade" glass with spectrum of natural jadeite</b>, p. 27, 2pp.]
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</li><li>[http://www.gia.edu/research-resources/gems-gemology/back-issue-archive/fall-1975.pdf Fall 1975 <b>Rare, nearly transparent, light gray faceted jadeite</b>, p. 73, 2pp.]
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</li>
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</ul>

Latest revision as of 17:11, 20 August 2012

Nephrite
Chemical composition Complex Ca Mg/Fe (calcium magnesium/iron) silicate
Crystal system Monoclinic
Habit Polycrystalline
Fracture Splintery
Hardness 6.5
Refractive index ±1.62
Specific gravity 2.90 - 3.20
Lustre Greasy to vitreous

Nephrite has been recognized as a separate type of jade since 1863. It is formed from aggregates of fibrous amphibole crystals. The structure they form is interlocking and tougher than steel. It's colors range from dark green iron rich varieties to cream colored magnesium rich varieties. It can be found blotchy, banded or singly colored. It is vary popular for carving and was used for weapons of the past.

Enhancements

Common enhancements to nephrite:

  • Fracture filling - wax - conceal cracks and fractures
  • Coatings - wax - to improve luster

Occurrence

Nephrite is found in Turkestan, Myanmar, Siberia (dark green rocks with black spots), Russia, China, New Zealand, Australia (black stones), USA, Canada, Mexico, Brazil, Taiwan, Zimbabwe (dark green), Italy, Poland, Germany and Switzerland. It has been carved by the Chinese for at least 2,000 years.

Sources consulted

  • Smithsonian Handbooks, Gemstones, Second Edition 2002

G&G Articles on Jade 1934-1980

The GIA has published all the G&G's from 1934 until 1980 online. The organization of the list by subject was done by Joseph Gill.