Nephrite
Nephrite (Greek - kidney) is a dense, fibrous aggregate variety of the tremolite-actinolite series that is tougher than
jadeite. It can be all colours, often with a yellow tint. The most valuable is green. But green colour of nephrite is often more subdued and darker than jadeite's green colour.
Nephrite is known as the toughest gem and carving material.
Nephrite is a readily available, more affordable alternative to jadeite.
General Information |
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A variety or type of: | Jade |
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Other Names/Trade Names: | |
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Chemical Formula | Walter Schumann, Gemstones of the world (2001) More from other references |
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Nephrite Treatments |
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Less commonly dyed than jadeite-jade because of its more compact structure, may be impregnated - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 5 |
Physical Properties of Nephrite |
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Mohs Hardness | 6 to 6.5Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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Specific Gravity | 2.90 to 3.10Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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Tenacity | BrittleWalter Schumann, Gemstones of the world (2001) |
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Cleavage Quality | NoneArthur Thomas, Gemstones (2009) |
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Fracture | SplinteryArthur Thomas, Gemstones (2009) |
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Optical Properties of Nephrite |
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Refractive Index | 1.600 to 1.627Walter Schumann, Gemstones of the world (2001) More from other references |
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Optical Character | Biaxial/-Arthur Thomas, Gemstones (2009) |
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Birefringence | 0.027 to often moreWalter Schumann, Gemstones of the world (2001) More from other references |
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Pleochroism | NilArthur Thomas, Gemstones (2009) |
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Dispersion | NilArthur Thomas, Gemstones (2009) |
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Chatoyancy | YesUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
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Colour |
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Colour (General) | Green, gray-green, reddish-brown, blackUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
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Transparency | Translucent,OpaqueUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
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Fluorescence & other light emissions |
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Fluorescence (General) | NoneWalter Schumann, Gemstones of the world (2001) |
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Crystallography of Nephrite |
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Crystal System | MonoclinicHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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Habit | FibrousHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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Geological Environment |
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Where found: | Occurs in serpentine rocks, and as river or beach pebbles.Walter Schumann, Gemstones of the world (2001) More from other references |
Further Information |
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Mineral information: | Nephrite information at mindat.org |
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Significant Gem Localities |
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| Australia | |
- District Council of Franklin Harbour
| Nichol (2000) | | Canada | |
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| Nichol (2000) |
| Nichol (2000) |
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| | | China | |
| | | Italy | |
| Nichol (2000) | | New Zealand | |
| | | Switzerland | |
| Nichol and Giess (2005) | | Taiwan | |
| Adams and Beck (2009) | | USA | |
- Santa Lucia Mts (Santa Lucia Range)
- Los Burros Mining District
| Paradise (1985) |
| Ward (1999) |
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