It usually is found as a botryoidal crust, a sparkling cauliflower aggregation or as minute spike-like crystals. Color is typically yellow, orange or brown, less commonly green, colorless or gray. Luster is resinous to adamantine. Crystals are transparent to translucent. Cleavage is rarely noticed.
Fracture is subconchoidal.
Hardness is 3.5 - 4. Streak is off white. Associated Minerals are wulfenite , limonite , calcite , barite , galena and secondary lead deposit minerals. Best Field Indicators are crystal habit, high luster, color, and density.