Yellow patches of the rare bismuth mineral bismutoferrite from the type locality: Pucher Shaft, Erzgebirge, Saxony, Germany. — Photo: David Hospital · CC BY-SA 4.0
Bismutoferrite
Bismutoferrite is an IMA-recognized mineral species in the silicate class, with the chemical formula Fe³⁺₂Bi(SiO₄)₂(OH).
It crystallizes in the monoclinic crystal system (space group Cm). It is a member of the Kaolinite structural group.
Key properties: specific gravity 4.47; Light green streak.
IMA symbol Bif, grandfathered status — known before the IMA’s founding, named in 1871.
Probably of hydrothermal origin, in veins cutting shale (Schneeberg, Germany).
It is found associated with Quartz, \chalcedony, " bismuth, cobaltite, arsenopyrite, chlorargyrite (Schneeberg, Germany); quartz, bismuth, galena, silver ores (Johanngeorgenstadt.
The name refers to BISMUTh and iron, (FERRum), in the composition.