Beyerite Locality: Siebenschlehen Mine (Shaft 10), Neustädtel, Schneeberg District, Erzgebirge, Saxony, Germany Yellow crystal clusters of Beyerite. Field of view 3 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Beyerite
Beyerite is an IMA-recognized mineral species in the carbonate class, with the chemical formula CaBi₂O₂(CO₃)₂.
It crystallizes in the orthorhombic crystal system (space group Immm). It is a member of the Bismutite structural group.
Key properties: Mohs hardness 2–3; specific gravity 6.56; White streak; Vitreous luster; optically uniaxial.
IMA symbol Bey, grandfathered status — known before the IMA’s founding, named in 1943.
Found as a rare secondary mineral in hydrothermal mineral deposits and granite pegmatites, produced through alteration of bismuth-bearing sulfides and sulfosalts.
It is found associated with Bismutite, bismutostibiconite, atelestite, preisingerite, pucherite, eulytite, namibite, clinobisvanite, bismutotantalite, bismuthinite, bismuth.
The mineral was named to honor Adolph Beyer (1743–1805), mining engineer and mineralogist, Schneeberg, Germany, who first recognized bismutite.