| 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 Watermelon Tourmaline |
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| Mohs Hardness | 7 to 7.5Gemdat.org, Management Team (2012) |
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| Specific Gravity | 2.90 to 3.40Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) |
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| Tenacity | BrittleGemdat.org, Management Team (2012) |
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| Cleavage Quality | NoneGemdat.org, Management Team (2012) |
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| Fracture | Uneven,Irregular,Conchoidal,Sub-ConchoidalGemdat.org, Management Team (2012) |
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| Optical Properties of Watermelon Tourmaline |
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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 | 0.017Arthur Thomas, Gemstones (2009) |
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| Colour |
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| Colour (General) | Green rims on red/pink coresGemdat.org, Management Team (2012) |
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| Transparency | TransparentGemdat.org, Management Team (2012) |
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| Lustre | VitreousGemdat.org, Management Team (2012) |
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| Fluorescence & other light emissions |
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| Fluorescence (Short Wave UV) | The red/pink cores may fluoresce chalky blue or creamy white depending on the activator. Sometimes specimens show both colors in patchy or zonal arrangement.King, Vandall T., Worldwide Tourmaline Responses to SW and LW UV Light (2009) Mineral News |
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| Crystallography of Watermelon Tourmaline |
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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: | Watermelon Tourmaline information at mindat.org |
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| Significant Gem Localities |
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| Brazil | | |
| Cassedanne and Roditi (1996) | | USA | |
- Mesa Grande Mining District
| Fisher, J. 2002. Gem and rare-element pegmatites of southern California. Mineralogical Record, Volume 33, Number 5: pages 390-396, photographs. | |
| Freeman (2005) | |
| Freeman (2005) |
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