Bismuthinite - Encyclopedia

    Class : Sulfides and sulfosalts
    Subclass : Sulfides
    Crystal System : Orthorhombic
    Chemistry : Bi2S3
    Rarity : Common

Bismuthinite is an accessory mineral of high temperature hydrothermal mineralization associated with granitoid intrusions, notably tin and tungsten deposits, which are also found in pegmatites (Madagascar), auriferous veins (Salsigne, France), and fluorite - siderite veins. It frequently accompanies native bismuth, arsenopyrite, cassiterite and wolframite. Its name derives from its chemical composition : bismuth. It is quite rarely presented in squat prismatic crystals with finely striated needles, reminiscent of the stibnite. Bismuthinite usually occurs as lamellar aggregates, cleavable foliated, fibrous or grainy masses, also similar to stibnite. It is a lead-gray to pewter-white mineral, often dull yellow or iridescent on the surface, which readily changes to bismutite on outcrops. It is a bismuth ore, often recovered as a by-product of gold or tin.

Main photo : Bismuthinite from Tazna Mine, Potosi, Bolivia © Fabre Minerals

Bismuthinite from Tazna Mine, Potosi, Bolivia © Tony Peterson
Bismuthinite from Schmiedestollen, Germany © Michael Förch
Bismuthinite and fluorite from Barbora Adit, Czech Republic © Petr Fuchs
Bismuthinite from Montroc, Tarn, France © Jean-Marie Laurent

Bismuthinite in the World

The finest samples come from the Bolivian tin province : Tazna (perfect 8 cm crystals), Llallagua, Huanuni. Other remarkable samples come from English Cornwall, from Ehrenfriedersdorf (Saxony, Germany) with acicular crystals of 10 cm, from Spind (Norway), as well as Malagasy pegmatites which contain large decimetric crystals often highly transformed into bismutite and bismite.

Bismuthinite in France

In France, centimetric blades of bismuthinite are found in Meymac (Corrèze) and in acicular microcrystals in Puy-les-Vignes (Haute-Vienne), Montroc and Moulinal (Tarn), Marsanges (Haute-Loire) and in many other localities.

Twinning and special crystallizations

No twin known for this mineral species.

Fakes and treatments

No fake identify for this mineral species.


Hardness : 2 to 2.5
Density : 6.78
Fracture : Irregular
Trace : Gray

TP : Opaque
RI : -
Birefringence : -
Optical character : None
Pleochroism : None
Fluorescence : None

Solubility : Nitric acid

Magnetism : Diamagnetic
Radioactivity : None