Stibnite

Stibnite

Stibnite in the American Museum of Natural History
General
Category	Mineral
Chemical formula	antimony sulfide (Sb₂S₃)
Identification
Colour	Steel gray to dull gray. Black iridiscent tarnish may be present.
Crystal habit	Massive, radiationg and elongated crystals. Massive and granular.
Crystal system	Orthorhombic
Cleavage	Perfect
Fracture	Small-scale subconchoidal
Mohs Scale hardness	2
Luster	Splendent on fresh crystals surfaces, otherwise metallic
Refractive index	Opaque
Pleochroism	N/A
Streak	Similar to colour
Specific gravity	4.56 - 4.62
Fusibility	?
Solubility	Souluble in hydrochloric acid
Major varieties
Metastibnite	Earthy, reddish deposits

Stibnite, sometimes also called antimonite, is a sulfide mineral. It crystallizes in the orthorhombic system, has hardness 2 and a grey colour. Its chemical composition is described by the formula Sb₂S₃

Stibnite is the most important source for the rare metal antimony. It is soluble in hydrochloric acid, and is tarnished by potassium hydroxide solution.

Small deposits of Stibnite are common, large ones are rare. It occurs in Canada, Mexico, Peru, Japan, China, Germany, Romania, Italy, France, England, Algeria, and Kalimantan, Borneo. In the United States it is found in Arkansas, Idaho, Nevada, California, and Alaska.

Spectacular, large iridescent stibnite crystals are found in Japan.

Stibnite

See also