Williamsite
Williamsite is a variety of Antigorite that has oil-green colour and is often included with black crystals of chromite or magnetite.
Williamsite is cut into cabochons and beads. It is also used as Jade simulant.
Williamsite is cut into cabochons and beads. It is also used as Jade simulant.
| General Information | ||||||||||||||||||||||
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| A variety or type of: | Antigorite, which is a variety of Serpentine | |||||||||||||||||||||
| Chemical Formula |
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| Physical Properties of Williamsite | ||||||||||||||||||||||
| Mohs Hardness | 4, Blue Chart Gem Identification (2010) +/-4 | |||||||||||||||||||||
| Specific Gravity | 2.51 to 2.63, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Cleavage Quality | Perfect, Handbook of mineralogy (2001) | |||||||||||||||||||||
| Fracture | Conchoidal,Splintery, Handbook of mineralogy (2001) | |||||||||||||||||||||
| Optical Properties of Williamsite | ||||||||||||||||||||||
| Refractive Index | 1.530 to 1.575, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Optical Character | Biaxial/-, Handbook of mineralogy (2001) | |||||||||||||||||||||
| Colour | ||||||||||||||||||||||
| Colour (General) | Intense green, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Causes of Colour | Green, Cr3+ around chromite inclusions, Pragmatic Spectroscopy For Gemologists (2011) | |||||||||||||||||||||
| Transparency | Translucent, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Lustre | Waxy,Silky,Resinous,Greasy,Dull (Earthy), Handbook of mineralogy (2001) | |||||||||||||||||||||
| Fluorescence & other light emissions | ||||||||||||||||||||||
| Fluorescence (Long-Wave UV) | Weak whitish-green, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Crystallography of Williamsite | ||||||||||||||||||||||
| Crystal System | Monoclinic, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Inclusions in Williamsite | ||||||||||||||||||||||
| Black octahedral chromite crystals - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 6 | ||||||||||||||||||||||
| Further Information | ||||||||||||||||||||||
| Mineral information: | Williamsite information at mindat.org | |||||||||||||||||||||