Wulfenite - PbMoO₄

Habit: Bright yellow, wax yellow, yellow orange, bright orange, red orange or bright red; also gray, grayish white, rarely white or colorless, green, pale to dark blue, reddish brown, brown or black. Crystals commonly square and flat tabular but may be elongated or pyramidal; can be granular or massive. Subadamantine to greasy luster; transparent to opaque. Yellowish white streak.

Environment: A secondary mineral found in the oxidized zone of deposits of lead- and molybdenum-containing minerals.

Etymology: Named after Franz Xavier Wulfen (1728-1805), an Austro-Hungarian Jesuit and mineralogist.

The US state of Arizona is a noted locality for wulfenite. At the Red Cloud Mine, in the silver district north of Yuma, wulfenite crystals form bright red chunky blades. Butterscotch-colored bladed crystals come from the Glove Mine, in the Santa Rita Mountains south of Tucson. These prized mineral specimens occur in a district famous for its lead­zinc-silver deposits.