Chemistry:Humite
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Humite | |
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![]() Humite specimen, Italy | |
General | |
Category | Nesosilicates |
Formula (repeating unit) | (Mg,Fe)7(SiO4)3(F,OH)2. |
Strunz classification | 9.AF.50 |
Crystal system | Orthorhombic |
Crystal class | Dipyramidal (mmm) H–M Symbol: (2/m 2/m 2/m) |
Space group | Pbnm |
Unit cell | a = 10.24, b = 20.72 c = 4.73 [Å]; Z = 4 |
Identification | |
Color | White, yellow, dark orange, brown |
Cleavage | Poor |
Fracture | Uneven to subconchoidal |
Tenacity | Brittle |
Mohs scale hardness | 6–6.5 |
|re|er}} | Vitreous |
Streak | White |
Diaphaneity | Transparent |
Specific gravity | 3.20 – 3.32 |
Optical properties | Biaxial (+) |
Refractive index | nα =1.607–1.643, nβ=1.619–1.653, nγ=1.639–1.675 |
Birefringence | 0.0320 |
2V angle | Calculated = 70–78°, measured = 68–81° |
Dispersion | Weak, r > v |
References | [1][2][3] |
Humite is a mineral found in the volcanically ejected masses of Vesuvius. It was first described in 1813 and named for Abraham Hume (1749–1838).[5]
See also
References
- ↑ Handbook of Mineralogy
- ↑ Webmineral data
- ↑ Mindat w/ locations
- ↑ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode: 2021MinM...85..291W.
- ↑ Deer, W.; Howie, R.; Zussman, J. (1997). Rock-forming Minerals: Volume 1A, Second Edition, Orthosilicates. Bath, UK: The Geological Society. ISBN 1-897799-88-8.
External links
![]() | Original source: https://en.wikipedia.org/wiki/Humite.
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