wolframite(n = noun.substance)iron manganese tungsten - a mineral consisting of iron and manganese tungstate in crystalline form; the principal ore of tungsten; found in quartz veins associated with granitic rocks;
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. [1913 Webster]