Simpsonite
Brazil
0.20 carats
© Rarestone.com
Simpsonite forms transparent to translucent, yellow, orange to brown, sometimes colourless tabular to short prismatic crystals with an adamantine lustre.
Simpsonite is cut into attractive, colourful, bright and durable gems, but the amount of facet rough is limited.
Simpsonite Gemstones by Colour
This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
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| General Information | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chemical Formula |
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| Physical Properties of Simpsonite | ||||||||||||||
| Mohs Hardness | 7 to 7.5, Gemstones of the world (2001) More from other references | |||||||||||||
| Specific Gravity | 5.90 to 7.30, Gemmological Tables (2004) More from other references | |||||||||||||
| Tenacity | Brittle, Gemstones (2009) | |||||||||||||
| Cleavage Quality | Indistinct, Gemstones (2009) | |||||||||||||
| Fracture | Conchoidal, Handbook of mineralogy (2001) | |||||||||||||
| Optical Properties of Simpsonite | ||||||||||||||
| Refractive Index | 1.994 to 2.040, Gemmological Tables (2004) More from other references | |||||||||||||
| Optical Character | Uniaxial/-, Gemmological Tables (2004) More from other references | |||||||||||||
| Birefringence | 0.046, Gemmological Tables (2004) More from other references | |||||||||||||
| Pleochroism | Nil, Gemstones (2009) | |||||||||||||
| Dispersion | Nil, Gemstones (2009) | |||||||||||||
| Colour | ||||||||||||||
| Colour (General) | Orange, colourless, white, brownish-yellow., Gemstones of the world (2001) More from other references | |||||||||||||
| Transparency | Translucent, Gemmological Tables (2004) More from other references | |||||||||||||
| Lustre | Adamantine,Vitreous, Gemstones of the world (2001) More from other references | |||||||||||||
| Fluorescence & other light emissions | ||||||||||||||
| Fluorescence (Short Wave UV) | Crystals from western Australia show a bright blue-white, Gems, Sixth Edition (2006) More from other references | |||||||||||||
| Crystallography of Simpsonite | ||||||||||||||
| Crystal System | Trigonal, Gemmological Tables (2004) More from other references | |||||||||||||
| Habit | Tabular to short prismatic, Gems, Sixth Edition (2006) More from other references | |||||||||||||
| Geological Environment | ||||||||||||||
| Where found: | Simpsonite occurs as an accessory mineral in some Ta-rich granite pegmatites., Gems, Sixth Edition (2006) More from other references | |||||||||||||
| Further Information | ||||||||||||||
| Mineral information: | Simpsonite information at mindat.org | |||||||||||||
| Significant Gem Localities | ||||||||||||||
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