Borate mineral
6+1⁄2-7
| Streak | White |
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| Diaphaneity | Transparent, translucent |
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| Specific gravity | 3.46 to 3.50 |
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| Density | 3.475-3.5 |
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| Optical properties | Biaxial (-) |
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| Refractive index | 1.665 to 1.712 |
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| Birefringence | 0.036 to 0.042 |
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| Pleochroism | Trichroism: green, light brown, dark brown |
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| 2V angle | 56° |
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| Dispersion | 0.018 |
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| Ultraviolet fluorescence | None |
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Sinhalite is a borate mineral with formula MgAl(BO4).[2]
Sinhalite was first found in Sri Lanka (Ceylon) in 1952, and was named from Sinhala - the Sanskrit name for Sri Lanka.[3]
Gemstone quality Sinhalite can also be found in Madagascar, Tanzania and Myanmar (Burma). The most commonly seen color of Sinhalite are white to gray, grayish-blue or a shade of brown ranging from pale to dark. Pale pink and brownish pink crystals can be found in Tanzania.
References
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ "Sinhalite". Mindat.org.
- ^ "Sinhalite gemstone information". Gemdat.org. Retrieved 21 March 2019.
