Chrysoprase
Chrysoprase is an attractive apple-green form of Chalcedony that is coloured by nickel. One of the most prized forms of Chalcedony.
Colour can fade in sunlight and when heated, colours may recover under moist storage.
Used as cabochons, for necklaces, and for ornamental objects. In earlier centuries, it was used as a luxurious decorative stone for interior decorations.
Colour can fade in sunlight and when heated, colours may recover under moist storage.
Used as cabochons, for necklaces, and for ornamental objects. In earlier centuries, it was used as a luxurious decorative stone for interior decorations.
| General Information | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| A variety or type of: | Chalcedony, which is a variety of Quartz | ||||||||||||||||||
| Chemical Formula |
| ||||||||||||||||||
| 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 | |||||||||||||||||||
| Physical Properties of Chrysoprase | |||||||||||||||||||
| Mohs Hardness | 6.5 to 7, Blue Chart Gem Identification (2010) | ||||||||||||||||||
| Specific Gravity | 2.58 to 2.64, Gemstones of the world (2001) More from other references | ||||||||||||||||||
| Tenacity | Brittle, Gemstones of the world (2001) | ||||||||||||||||||
| Cleavage Quality | None, Gemstones of the world (2001) | ||||||||||||||||||
| Optical Properties of Chrysoprase | |||||||||||||||||||
| Refractive Index | 1.530 to 1.543, Blue Chart Gem Identification (2010) | ||||||||||||||||||
| Optical Character | Uniaxial/+, Gemmological Tables (2004) | ||||||||||||||||||
| Birefringence | up to to 0.004, Gemstones of the world (2001) | ||||||||||||||||||
| Pleochroism | Absent, Gemstones of the world (2001) | ||||||||||||||||||
| Dispersion | None, Gemstones of the world (2001) | ||||||||||||||||||
| Colour | |||||||||||||||||||
| Colour (General) | Green, Gemmological Tables (2004) More from other references | ||||||||||||||||||
| Colour (Chelsea Filter) | Greenish, Blue 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,Opaque, Gemmological Tables (2004) More from other references | ||||||||||||||||||
| Fluorescence & other light emissions | |||||||||||||||||||
| Fluorescence (General) | None, Gemstones of the world (2001) | ||||||||||||||||||
| Crystallography of Chrysoprase | |||||||||||||||||||
| Crystal System | Trigonal, Gemmological Tables (2004) | ||||||||||||||||||
| Habit | Microcrystalline aggregates, Gemstones 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 | Chrysoprase - Locality: Unknown | ||||||||||||||||||
| Further Information | |||||||||||||||||||
| Mineral information: | Chrysoprase information at mindat.org | ||||||||||||||||||
| Significant Gem Localities | |||||||||||||||||||
| |||||||||||||||||||