They were formerly confused under the names green lead ore and brown lead ore (German, Grünbleierz and Braunbleierz). The phosphate was first distinguished chemically by M. H. Kiaproth in 1784, and it was named pyromorphite by J. F. L. Hausmann in 1813.
The color of the mineral is usually some bright shade of green, yellow or brown, and the luster is resinous. The hardness is 3, and the specific gravity 6.5 - 7.1. Owing to isomorphous replacement of the phosphorus by arsenic there may be a gradual passage from pyromorphite to mimetite. Varieties containing calcium isomorphously replacing lead are lower in density (specific gravity 5.9 - 6.5) and usually lighter in color; they bear the names polysphaerite (because of the globular form), miesite from Mies in Bohemia, nussierite from Nuizière, Chénelette, near Beaujeu, Rhône, France, and cherokine from Cherokee County in Georgia.