India
6.86 carats
© gemselect.com
General Information | |||||||||||||||||||||
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A variety or type of: | Chalcedony, which is a variety of Quartz | ||||||||||||||||||||
Chemical Formula |
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Chrysoprase Treatments | |||||||||||||||||||||
Dyed green (chromium) - chelsea: pinkish to reddish. Might be dyed with nickel-rich solution: standard tests limited - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 7 | |||||||||||||||||||||
Chrysoprase Simulants | |||||||||||||||||||||
Grayish chalcedony is soaked in mixture of water, acid, chromium or nickel compounds, then heated and dryed. This will create a material with green to bluish green colour. - GIA 2019 | |||||||||||||||||||||
Physical Properties of Chrysoprase | |||||||||||||||||||||
Mohs Hardness | 6.5 to 7Blue Chart Gem Identification (2010) , | ||||||||||||||||||||
Specific Gravity | 2.58 to 2.64Gemstones of the world (2001) , More from other references | ||||||||||||||||||||
Tenacity | BrittleGemstones of the world (2001) , | ||||||||||||||||||||
Cleavage Quality | NoneGemstones of the world (2001) , | ||||||||||||||||||||
Optical Properties of Chrysoprase | |||||||||||||||||||||
Refractive Index | 1.530 to 1.543Blue Chart Gem Identification (2010) , | ||||||||||||||||||||
Optical Character | Uniaxial/+Gemmological Tables (2004) , | ||||||||||||||||||||
Birefringence | up to to 0.004Gemstones of the world (2001) , | ||||||||||||||||||||
Pleochroism | AbsentGemstones of the world (2001) , | ||||||||||||||||||||
Dispersion | NoneGemstones of the world (2001) , | ||||||||||||||||||||
Colour | |||||||||||||||||||||
Colour (General) | Colored by nickel: (yellowish)-greenBlue Chart Gem Identification (2010) , More from other references | ||||||||||||||||||||
Colour (Chelsea Filter) | GreenishBlue Chart Gem Identification (2010) , | ||||||||||||||||||||
Causes of Colour | Green colour is caused by microscopic inclusions of silicates with Ni-bearing layers (willemseite, népouite, etc).Management Team (2012) , More from other references | ||||||||||||||||||||
Transparency | Translucent,OpaqueGemmological Tables (2004) , More from other references | ||||||||||||||||||||
Fluorescence & other light emissions | |||||||||||||||||||||
Fluorescence (General) | NoneGemstones of the world (2001) , | ||||||||||||||||||||
Crystallography of Chrysoprase | |||||||||||||||||||||
Crystal System | TrigonalGemmological Tables (2004) , | ||||||||||||||||||||
Habit | Microcrystalline aggregatesGemstones of the world (2001) , | ||||||||||||||||||||
Geological Environment | |||||||||||||||||||||
Where found: | It occurs in quartz veins in nickel-bearing rocks or in veins in laterites overlying Ni-bearing serpentinites (Queensland) and associated with jadeite in veins in serpentinized gabbro and ultramafic inclusions (Lower Silesia.)Gems, Sixth Edition (2006) , | ||||||||||||||||||||
Spectrographic Data | |||||||||||||||||||||
Calculated Spectra: Click spectra for more information | |||||||||||||||||||||
Further Information | |||||||||||||||||||||
Mineral information: | Chrysoprase information at mindat.org | ||||||||||||||||||||
Significant Gem Localities | |||||||||||||||||||||
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