Freibergite

(repeating unit)Cu12Sb4S13IMA symbolFb[1]Strunz classification2.GB.05Crystal systemCubicCrystal classHextetrahedral (43m)
H-M symbol: (4 3m)Space groupI43mIdentificationFormula mass1,929.46 g/molColorSteel gray to blackCrystal habitmassive to well formed crystalsCleavageNoneFractureUnevenMohs scale hardness3.5–4LusterMetallicStreakreddish blackDiaphaneityOpaque

Freibergite is a complex sulfosalt mineral of silver, copper, iron, antimony and arsenic with formula (Ag,Cu,Fe)12(Sb,As)4S13. It has cubic crystals and is formed in hydrothermal deposits. It forms one solid solution series with tetrahedrite and another with argentotennantite. Freibergite is an opaque, metallic steel grey to black and leaves a reddish-black streak. It has a Mohs hardness of 3.5 to 4.0 and a specific gravity of 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 the type locality at Freiberg, Saxony.

References

  1. ^ 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.
  • Mineral handbook
  • Webmineral
  • Mindat
Wikimedia Commons has media related to Freibergite.


  • v
  • t
  • e