| General Information |
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| A variety or type of: | Tourmaline |
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| Varieties/Types: | |
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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 Elbaite |
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| Mohs Hardness | 7Anthony et al, Handbook of mineralogy (2001) |
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| Specific Gravity | 2.90 to 3.10Anthony et al, Handbook of mineralogy (2001) |
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| Tenacity | BrittleAnthony et al, Handbook of mineralogy (2001) |
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| Cleavage Quality | IndistinctWalter Schumann, Gemstones of the world (2001) More from other references |
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| Fracture | Uneven,ConchoidalAnthony et al, Handbook of mineralogy (2001) |
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| Optical Properties of Elbaite |
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| Refractive Index | 1.614 to 1.666Walter Schumann, Gemstones of the world (2001) |
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| Optical Character | Uniaxial/-Anthony et al, Handbook of mineralogy (2001) |
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| Birefringence | 0.014 to 0.032Walter Schumann, Gemstones of the world (2001) |
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| Pleochroism | Pink, pale green, pale to deep blue - colorless, yellow, olive-green, purplishAnthony et al, Handbook of mineralogy (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) | Green, blue, red, orange, yellow, colorless, zoning common parallel to trigonal outline; colorless in thin section.Anthony et al, Handbook of mineralogy (2001) |
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| Causes of Colour | Green, Fe2+ and Ti4+ in octahedral coordination, influence of various charge transfer processes involving iron is a distinct possibility. Yellow-green, Mn2+-O-Ti4+ charge transfer. Greenish yellow, Mn2+ in octahedral coordination (rare). Orange, yellow + pink. Pink to red, related to manganese, generally believed to be due to Mn3+ in octahedral coordination, sometimes caused by irradiation. Brown, Fe2+→Ti4+ charge transferW. William Hanneman, Pragmatic Spectroscopy For Gemologists (2011) |
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| Transparency | Transparent,TranslucentAnthony et al, Handbook of mineralogy (2001) |
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| Lustre | Vitreous,ResinousAnthony et al, Handbook of mineralogy (2001) |
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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 Elbaite |
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| Crystal System | HexagonalAnthony et al, Handbook of mineralogy (2001) |
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| Habit | Crystals prismatic to acicular, with prominent trigonal prism and pyramid, to 1.6 m, commonly hemimorphic. Also radial,
fibrous, and massive.Anthony et al, Handbook of mineralogy (2001) |
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| Geological Environment |
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| Where found: | In granites, granite pegmatites, and some metamorphic rocks; in high-temperature hydrothermal veins; detrital in sediments.Anthony et al, Handbook of mineralogy (2001) |
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| Further Information |
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| Mineral information: | Elbaite information at mindat.org |
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| Significant Gem Localities |
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| Brazil | | |
| [var: Paraíba Tourmaline] Wilson, W. E. (2002): Cuprian elbaite from the Batalha Mine, Paraíba, Brazil. Mineralogical Record, 33: 127-137 | | Myanmar | | |
| Ted Themelis (2008) Gems & mines of Mogok | |
| Ted Themelis (2008) Gems & mines of Mogok |
- Dattaw-taung (Dattaw hill)
| Ted Themelis (2008) Gems & mines of Mogok | |
| Ted Themelis (2008) Gems & mines of Mogok | |
| Ted Themelis (2008) Gems & mines of Mogok | | USA | |
- Mesa Grande Mining District
| Min.Rec.:20(5):399. / Foord, E.E. (1977): Famous mineral localities. The Himalaya Dike System. Mineralogical Record 8, 461-475 |
- Tourmaline Queen Mountain (Pala Mtn; Queen Mtn)
| Fisher, J. 2002. Gem and rare-element pegmatites of southern California. Mineralogical Record, Vol. 33: pages 378-381. |
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