What is the X in X-mas?
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 Pribram, Czech Republic; Yuma County, Ariz., U.S.; and Mapimi, Durango, Mex. Other localities include Germany, Austria, Sardinia, and Australia.