Admontite is a hydrated magnesium borate mineral with formula MgB6O10·7H2O.
Admontite | |
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General | |
Category | Nesoborates |
Formula (repeating unit) | MgB6O10·7H2O[1] or MgB6O7(OH)6·4H2O[2] |
IMA symbol | Amt[3] |
Strunz classification | 6.FA.15 |
Dana classification | 26.6.3.1 |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | P21/c |
Identification | |
Color | colorless |
Cleavage | Absent |
Fracture | Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz) |
Mohs scale hardness | 2 - 3 - Gypsum-Calcite |
Streak | White |
Density | 1.82 - 1.87, Average = 1.84 |
Optical properties | Biaxial (−) |
Refractive index | nα = 1.442 nγ = 1.504 |
Birefringence | δ = 0.062 |
Dispersion | None |
References | [2][1][4] |
Occurrence - In a gypsum deposit. Associations: gypsum, anhydrite, hexahydrite, löweite, eugsterite, pyrite, quartz.
It is named after Admont, Austria. Its Mohs scale rating is 2 to 3.
See also
editReferences
editLook up admontite in Wiktionary, the free dictionary.
- ^ a b Handbook of Mineralogy
- ^ a b Mindat.org
- ^ 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.
- ^ Webmineral data