Wulfenite is a lead molybdate mineral with the chemical formula PbMoO4. It is most often found as thin tabular crystals with a bright orange-red to yellow-orange color, sometimes brown, although the color can be highly variable. In its yellow form it is sometimes called "yellow lead ore". The mineral was first described in 1845 for an occurrence in Bad Bleiberg, Austria, and was named after Franz Xaver von Wulfen, an Austrian mineralogist. This specimen of wulfenite, embedded in a small amount of matrix, measures 2.2 cm × 1.7 cm × 0.3 cm (0.87 in × 0.67 in × 0.12 in) in size and was extracted from the Red Cloud mine near Yuma, Arizona.Photograph credit: Ivar Leidus