Wulfenite is named for Franz Xavier von Wulfen (1728–1805), an Austrian mineralogist. Wulfenite crystallizes in the tetragonal system, often occurring as stubby, pyramidal or tabular crystals. It also occurs as earthy, granular masses. It is found in many localities, associated with lead ores as a secondary mineral associated with the oxidized zone of lead deposits. It is also a secondary ore of molybdenum, and is sought by collectors. Crystals are deep red in color and usually very well formed.