| General Information |
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| A variety or type of: | Tourmaline |
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| Chemical Formula | | Na(Li | | Al | | )Al | | (Si | | O | | )(BO | | ) | | (OH) | | (OH) |
Gemdat.org, Management Team (2012) More from other references |
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| Physical Properties of Achroite |
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| Mohs Hardness | 7 to 7.5Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
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| Specific Gravity | 2.90 to 3.40Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
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| Tenacity | BrittleWalter Schumann, Gemstones of the world (2001) |
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| Cleavage Quality | IndistinctWalter Schumann, Gemstones of the world (2001) |
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| Fracture | Uneven,ConchoidalWalter Schumann, Gemstones of the world (2001) |
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| Optical Properties of Achroite |
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| Refractive Index | 1.614 to 1.666Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
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| Optical Character | Uniaxial/-Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
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| Birefringence | 0.014 to 0.040Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
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| Dispersion | 0.017Walter Schumann, Gemstones of the world (2001) |
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| Colour |
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| Colour (General) | ColorlessHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
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| Transparency | Transparent,Translucent,OpaqueUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
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| Lustre | Vitreousgemdat.org, Editorial Team (2012) |
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| Fluorescence & other light emissions |
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| Fluorescence (General) | Weak to noneWalter Schumann, Gemstones of the world (2001) |
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| Crystallography of Achroite |
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| Crystal System | Trigonalgemdat.org, Editorial Team (2012) |
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| Habit | Long crystals with triangular cross section and rounded sides, definite striation parallel to main axisWalter Schumann, Gemstones of the world (2001) |
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| Further Information |
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| Mineral information: | Achroite information at mindat.org |
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| Significant Gem Localities |
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| Afghanistan | | |
| Bowersox and Chamberlin (1995) | | USA | |
- Warner Springs Mining District
| Laurs (2001, 2002, 2004) | |
| Freeman (2005) | |
| Freeman (2005) |
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