Bieberite , Bismuth Locality: Schlema, Schlema-Hartenstein District, Erzgebirge, Saxony, Germany Original description: A heavy 4.4 by 2.7 cms mass of mainly grey Bismuth covered by a thin film of pinkish Bieberite from an old classic locality. JSS specimen and photo. — Photo: John Sobolewski (JSS) · CC BY 3.0
Bieberite
A pinkish-red cobalt sulfate heptahydrate named for the copper deposit at Bieber, Hesse, Germany.
Intro adapted from Wikipedia (CC BY-SA).
Bieberite is an IMA-recognized mineral species in the sulfate class, with the chemical formula Co(SO₄)·7H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/c). It is a member of the Melanterite structural group.
Key properties: Mohs hardness 2; specific gravity 1.96; Vitreous luster; optically biaxial.
IMA symbol Bie, grandfathered status — known before the IMA’s founding, named in 1845.
An uncommon oxidation product of cobalt-bearing sulfide–arsenides.
It is found associated with Erythrite, annabergite, pharmacolite, cobaltite, linnaeite.
The name refers to its first-noted occurrence at Bieber, Germany.