Mineral, Pb5(PO4)3Cl; sp. gr. 6.5–7.1; hardness 3.5–4.0; hexagonal; various shades of green, yellow, and brown; white streak; vitreous lustre; crystals prismatic and often hollow, or barrel-shaped, forming aggregates or crusts, also occurs granular, fibrous or globular; cleavage prismatic in traces; a secondary mineral occurring in the oxidized zones of veins containing lead minerals, often associated with mimetite and anglesite, and galena.