Phyllosilicate (sheet silicate)
Specific gravity: 4.47
Colour: yellow, green
Bismutoferrite is probably of hydrothermal origin.
At Johanngeorgenstadt, Erzgebirge District, Saxony, Germany, bismutoferrite is associated with quartz, bismuth, galena and silver ores.
At the type locality, Schneeberg, Erzgebirge District, Saxony, Germany, bismutoferrite occurs in veins cutting shale, associated with quartz/chalcedony, bismuth, cobaltite, arsenopyrite and chlorargyrite.
At the Lodi #4 claim, California, USA, bismutoferrite is associated with clinobisvanite.
Common impurities: Al,As