pyromorphite

{{Infobox mineral | name = Pyromorphite | category = Phosphate mineral Apatite group | boxwidth = | image = Pyromorphite - Santa Eufemia, Cordoba, Spain.jpg | imagesize = 260px | caption = | formula = Pb5(PO4)3Cl | IMAsymbol = Pym | molweight = | strunz = 8.BN.05 | system = Hexagonal | class = Dipyramidal (6/m) (same H-M symbol) | symmetry = P63/m | color = Dark green to grass-green or green, yellow, yellow-orange, reddish orange, yellow-brown, greenish-yellow or yellowish-green, shades of brown, tan, grayish, white and may be colorless; colourless or faintly tinted in transmitted light. | habit = Prismatic to acicular crystals, globular to reniform | twinning = Rarely on {112} | cleavage = Imperfect- [101] | fracture = Uneven to sub-conchoidal | tenacity = Brittle | mohs = 3.5–4 | luster = Resinous to subadamantine | polish = | refractive = nω = 2.058 nε = 2.048 | opticalprop = Uniaxial (−) May be anomalously biaxial (−) | birefringence = δ = 0.010 | dispersion = | pleochroism = Weak | fluorescence= May fluoresce yellow to orange under LW and SW UV | absorption = | streak = White | gravity = 7.04 measured, 7.14 calculated | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent to translucent | other = Piezoelectric if biaxial | references = }}

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.