WULFENITE

lead molybdate, PbMoO4, a minor source of molybdenum and the second most common molybdenum mineral. It occurs in the oxidized zone of lead and molybdenum deposits. Fine crystals have been found at Prbram, Czech Republic; Yuma County, Ariz., U.S.; and Mapimi, Durango, Mex. Other localities include Germany, Austria, Sardinia, and Australia. Wulfenite ordinarily crystallizes as thin, beveled, square plates that have a resinous to adamantine lustre, and they are yellow to orange in colour. The Mohs hardness is 3; specific gravity, 6.57; and crystal system, tetragonal.