Luster is vitreous. Crystals are translucent. Crystal System is monoclinic. Crystal Habits include platy or prismatic to acicular crystals and radiating fibrous masses and crusts. Cleavage is not observed.
Fracture is uneven.
Streak is pale yellow. Associated Minerals are malachite , cerussite , mimetite and other secondary arsenate minerals. Notable Occurrence is limited to Tsumeb, Namibia. Best Field Indicators are color, crystal habit, density, yellow streak and locality.