wolframite

Any of several red-brown to black minerals with the general formula (Fe,Mn)WO₄, which constitute a major source of tungsten.

See wolfram.

Tungstate of iron and manganese, generally of a brownish or grayish black color, submetallic luster, and high specific gravity. It occurs in cleavable masses, and also crystallized. Called also wolfram.

A mineral that consists of a tungstate of iron and manganese; (Fe,Mn)WO4.

a mineral consisting of iron and manganese tungstate in crystalline form; the principal ore of tungsten; found in quartz veins associated with granitic rocks