Mineral, PbCO3; sp. gr. 6.4–6.6; hardness 3.0–3.5; orthorhombic; usually white or grey; white streak; adamantine lustre; crystals often prismatic or tabular, also acicular, but can also occur granular, massive, and compact; cleavage good {110}, {021}; of secondary origin in the oxidized zone of lead veins, associated with anglesite, galena, smithsonite, pyromorphite, and sphalerite; soluble (with effervescence) in warm, dilute nitric acid. It is an ore mineral of lead.