Pumpellyite Subgroup
Pumpellyite is named after Raphael Pumpelly, pioneer student of the detailed paragenesis of the copper minerals of the Keweenawan Peninsula, Michigan, where the mineral was discovered. Pumpellyite is Michigan's State Gemstone.
Pumpellyite forms translucent to opaque, blue-green, olive green to white fibrous to lamellar masses with glassy lustre.
Pumpellyite can be easily polished and cut into cabochons.
Pumpellyite forms translucent to opaque, blue-green, olive green to white fibrous to lamellar masses with glassy lustre.
Pumpellyite can be easily polished and cut into cabochons.
| General Information | ||||||||||||||||||||||||||||||
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| Varieties/Types: | ||||||||||||||||||||||||||||||
| Chemical Formula |
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| Physical Properties of Pumpellyite Subgroup | ||||||||||||||||||||||||||||||
| Mohs Hardness | 5 to 6, Gemmological Tables (2004) | |||||||||||||||||||||||||||||
| Specific Gravity | 3.20 to 3.30, Gemmological Tables (2004) | |||||||||||||||||||||||||||||
| Optical Properties of Pumpellyite Subgroup | ||||||||||||||||||||||||||||||
| Refractive Index | 1.674 to 1.764, Gemmological Tables (2004) | |||||||||||||||||||||||||||||
| Optical Character | Biaxial/+, Gemmological Tables (2004) | |||||||||||||||||||||||||||||
| Birefringence | 0.014 to 0.016, Gemmological Tables (2004) | |||||||||||||||||||||||||||||
| Colour | ||||||||||||||||||||||||||||||
| Colour (General) | Green, white, Gemmological Tables (2004) | |||||||||||||||||||||||||||||
| Causes of Colour | Green (chlorastrolite), Fe2+-O-Fe3+ charge transfer coordination, plus Fe2+, Pragmatic Spectroscopy For Gemologists (2011) | |||||||||||||||||||||||||||||
| Transparency | Opaque, Gemmological Tables (2004) | |||||||||||||||||||||||||||||
| Further Information | ||||||||||||||||||||||||||||||
| Mineral information: | Pumpellyite Subgroup information at mindat.org | |||||||||||||||||||||||||||||