Freibergite
Appearance
Freibergite | |
---|---|
General | |
Category | Sulfosalt minerals |
Formula (repeating unit) | Cu12Sb4S13 |
IMA symbol | Fb[1] |
Strunz classification | 2.GB.05 |
Crystal system | Cubic |
Crystal class | Hextetrahedral (43m) H-M symbol:(43m) |
Space group | I43m |
Identification | |
Formula mass | 1,929.46 g/mol |
Color | Steel gray to black |
Crystal habit | massive to well formed crystals |
Cleavage | None |
Fracture | Uneven |
Mohs scalehardness | 3.5–4 |
Luster | Metallic |
Streak | reddish black |
Diaphaneity | Opaque |
Freibergiteis a complexsulfosaltmineral ofsilver,copper,iron,antimonyandarsenicwith formula(Ag,Cu,Fe)12(Sb,As)4S13.It hascubiccrystals and is formed inhydrothermaldeposits. It forms onesolid solutionseries withtetrahedriteand another withargentotennantite.Freibergite is an opaque, metallic steel grey to black and leaves a reddish-black streak. It has aMohs hardnessof 3.5 to 4.0 and aspecific gravityof 4.85 to 5. It is typically massive to granular in habit with no cleavage and an irregular fracture.
The mineral was first described in 1853 from an occurrence in the silver mines of thetype localityatFreiberg, Saxony.
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.S2CID235729616.
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