Pyromorphite is a mineral species composed of lead chlorophosphate: Pb₅(PO₄)₃Cl, sometimes occurring in sufficient abundance to be mined as an ore of lead. Crystals are common, and have the form of a hexagonal prism terminated by the basal planes, sometimes combined with narrow faces of a hexagonal pyramid. Crystals with a barrel-like curvature are not uncommon. Globular and reniform masses are also found. It is part of a series with two other minerals: mimetite (Pb₅(AsO₄)₃Cl) and vanadinite (Pb₅(VO₄)₃Cl), the resemblance in external characters is so close that, as a rule, it is only possible to distinguish between them by chemical tests.