Hisingerite
Hisingerite | |
---|---|
General | |
Category | Silicate mineral |
Formula (repeating unit) | FeIII2Si2O5(OH)4 · 2 H2O |
IMA symbol | Hsg[1] |
Strunz classification | 9.ED.10 |
Crystal system | Monoclinic Unknown space group |
Unit cell | a = 5.4, b = 9.03 c = 14.99 [Å]; β = 98.32°; Z = 4 |
Identification | |
Color | Black, brownish-black |
Crystal habit | Massive, compact; acicular, may be minutely spherical. |
Cleavage | None |
Fracture | Conchoidal |
Tenacity | Brittle |
Mohs scale hardness | 2.5 - 3.0 |
Luster | Vitreous, resinous, greasy |
Streak | Yellowish brown, green |
Diaphaneity | Transparent to translucent |
Specific gravity | 2.43 - 2.67 |
Optical properties | Biaxial (-) |
Refractive index | nα = 1.715 nγ = 1.730 |
Birefringence | δ = 0.015 |
References | [2][3][4] |
Hisingerite is an iron(III) phyllosilicate mineral with formula FeIII2Si2O5(OH)4 · 2 H2O. A black or dark brown, lustrous secondary mineral, it is formed by the weathering or hydrothermal alteration of other iron silicate and sulfide minerals.[2]
It was first described in 1828 for an occurrence in Riddarhyttan, Vastmanland, Sweden. It was named after Wilhelm Hisinger (1766–1852), a Swedish chemist.[4]
There are also aluminian hisingerite variety in which one of the iron atoms is replaced by aluminium and chrome-alumina-hisingerite variety in which chromium substitutes for iron.[3]
References[]
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85: 291–320.
- ^ a b Handbook of Mineralogy
- ^ a b Mindat.org
- ^ a b Webmineral
Categories:
- Iron(III) minerals
- Phyllosilicates
- Silicate mineral stubs