| General Information |
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| A variety or type of: | Tourmaline |
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| Other Names/Trade Names: | |
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| Chemical Formula | | Na(Li | | Al | | )Al | | (Si | | O | | )(BO | | ) | | (OH) | | (OH) |
Gemdat.org, Management Team (2012) |
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| Verdelite Treatments |
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| Routinely heat-treated to lighten the color - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 5 |
| Physical Properties of Verdelite |
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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 | BrittleMichael O’Donoghue, Gems, Sixth Edition (2006) |
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| Cleavage Quality | IndistinctWalter Schumann, Gemstones of the world (2001) |
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| Fracture | Sub-ConchoidalArthur Thomas, Gemstones (2009) |
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| Optical Properties of Verdelite |
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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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| Pleochroism | Strong: dark green - yellow-greenWalter Schumann, Gemstones of the world (2001) |
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| Dispersion | 0.017Walter Schumann, Gemstones of the world (2001) |
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| Colour |
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| Colour (General) | GreenHerve 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 | VitreousArthur Thomas, Gemstones (2009) |
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| Crystallography of Verdelite |
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| Crystal System | TrigonalHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) |
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| Habit | Prismatic to acicular crystalsMichael O’Donoghue, Gems, Sixth Edition (2006) |
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| Further Information |
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| Mineral information: | Verdelite information at mindat.org |
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| Significant Gem Localities |
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| Afghanistan | | |
| Glas (2002) | | Brazil | | |
| Cassedanne and Roditi (1996) | |
| Menezes (2009) | | Mozambique | | |
| Henn and Bank (1997) | |
| Henn and Bank (1997) | |
| Schafer and Arlt (2000) | | Sri Lanka | | |
| | | Tajikistan | | |
| Skrigitil (1996) | | USA | |
- Tourmaline Queen Mountain (Pala Mtn; Queen Mtn)
| Fisher et al. (1999) |
- Warner Springs Mining District
| Laurs (2001, 2002, 2004) | |
| Freeman (2005) |
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