Musgravite
Musgravite or magnesiotaaffeite-6N’3S is a rare oxide mineral used as a gemstone. Its type locality is the Ernabella Mission, Musgrave Ranges, South Australia, for which it was named following its discovery in 1967.[2] It is a member of the taaffeite family of minerals,[2][1] and its chemical formula is Be(Mg, Fe, Zn)2Al6O12. Its hardness is 8 to 8.5 on the Mohs scale.[2] Due to its rarity, the mineral can sell for roughly USD$35,000 per carat.
| Musgravite | |
|---|---|
 Musgravite from Sri Lanka | |
| General | |
| Category | Oxide minerals |
| Formula (repeating unit) | (Mg,Fe,Zn)2BeAl6O12 |
| Strunz classification | 04.FC.25 |
| Crystal system | Trigonal |
| Identification | |
| Color | Grey green to green |
| Fracture | Conchoidal |
| Mohs scale hardness | 8–8.5 |
| Luster | Vitreous |
| Diaphaneity | Transparent |
| Specific gravity | 3.62–3.68 |
| Optical properties | Uniaxial |
| Refractive index | nω = 1.739, nε = 1.735 |
| Birefringence | δ = 0.014 to 0.016 |
| References | [1][2] |
See also
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