Humite
Appearance
Humite | |
---|---|
General | |
Category | Nesosilicates |
Formula (repeating unit) | (Mg,Fe)7(SiO4)3(F,OH)2. |
IMA symbol | Hu[1] |
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 |
Luster | Vitreous |
Streak | White |
Diaphaneity | Transparent |
Specific gravity | 3.20 – 3.32 |
Optical properties | Biaxial (+) |
Refractive index | n |
Birefringence | 0.0320 |
2V angle | Calculated = 70–78°, measured = 68–81° |
Dispersion | Weak, r > v |
References | [2][3][4] |
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
[edit]References
[edit]- ^ 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.
- ^ Handbook of Mineralogy
- ^ Webmineral data
- ^ Mindat w/ locations
- ^ 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
[edit]Media related to Humite at Wikimedia Commons