Wolframite
Wolframite
General
Category	Mineral
Chemical formula	(Fe,Mn)WO4
Identification
Colour	Black (ferberite) to brown (huebnerite)
Crystal habit	Tabular crystals, sometimse prismatic
Crystal system	Monoclinic 2/m
Cleavage	Perfect 010
Fracture	Uneven to rough
Mohs Scale hardness	4-4.5
Luster	Submetallic to resinous
Refractive index	Opaque
Pleochroism	None
Streak	Black to brown
Specific gravity	7 - 7.5
Fusibility	3 - 4 to magnetic globule
Solubility	insoluble

Wolframite (Fe,Mn)WO₄, is an iron manganese tungstate mineral that is the intermediate between ferberite (Fe²⁺ rich) and huebernite (Mn²⁺ rich). Along with scheelite, the wolframite series are the most important tungsten ore minerals. Wolframite is found in quartz veins and pegmatites associated with granitic intrusives. Associated minerals include cassiterite, scheelite, bismuth, quartz, pyrite, galena, sphalerite, and arsenopyrite.

It was historically found in Bohemia, Saxony, and Cornwall. China reportedly has the world's largest supply of tungsten ore with about 60%. Other producers are Russia, Australia, Thailand, Korea, Bolivia, and the United States.

The name comes from German wolfram for tungsten and provides the chemical symbol, W, for tungsten.

See also

• List of minerals