What is Native Bismuth?
Native bismuth is a soft trigonal metal known for bright metallic surfaces, heavy density and colourful iridescent tarnish.
Mineralogy and crystal structure
Reference formula: Bi. Native bismuth has a trigonal structure and commonly occurs with bismuthinite, wolframite, cassiterite and native elements. Iridescent colours are usually a surface film rather than the intrinsic colour of fresh bismuth. Native Bismuth is classified with elements and has a trigonal crystal system. Typical hardness is 2–2.5 on the Mohs scale and specific gravity is approximately 9.6–9.8.
Colour, lustre and habit
Typical colours include silver-white, pinkish, iridescent. The usual granular, massive, crystalline habit and metallic lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Native Bismuth forms in or is associated with hydrothermal veins, granite pegmatites, tin-tungsten deposits and bismuth-rich sulfide assemblages. Important documented localities include Germany, Bolivia, Peru, China, Canada, Australia and the United States.
A pink-tinted metal with a collector's sheen
Native bismuth looks familiar and otherworldly at once: a heavy silver-white metal can develop pink, yellow or blue surface colours while preserving the chemistry of a specialised ore system.
Collecting and care
Soft and brittle: protect from scratches, avoid acids and do not grind dusty material.
