Wulfenite is a lead with the formula Pb 4. It can be 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".
It 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 associated with the oxidized zone of lead deposits. It is also a secondary ore of molybdenum , and is sought by collectors.