Chemical Formula: Pb5(PO4)3Cl

Chemical Name: Lead Chlorophosphate

Mineral Class: Phosphate

Mineral Notes: Pyromorphite is analogous to Mimetite with the phosphate (PO4) 3- ion replacing the arsenate anion. Although the properties of the two minerals are therefore almost the same, colour can usually be used to distinguish between the two, Mimetite being yellow-brown and Pyromorphite being yellow-green. It is a secondary mineral ocassionally mined as an ore of lead.  

Description: A honeycomb-like matrix whose structure is mainly made of intergrown Mimetite crystals. On top sit clusters of large, tear-drop shaped crystals of Pyromorphite. These have an attractive apple-green clour and a waxy luster. Some of the crystals are twinned.

Location: Mexico Mine, Roughton Gill, Caldbeck Fells, England.