Pyromorphite, Pb5(PO4)3Cl (Lead Chlorophosphate), is analogous to Mimetite with the Phosphate (PO4) 3- ion replacing the Arsenate cation. Although the properties of the two minerals are almost the same because of this, colour can usually be used to distinguish between the two, Mimetite being yellow and Pyromorphite being yellow-green. It is a secondary mineral ocassionally used as an ore of lead. 

Description: A pale brown crystalline matrix on which sits an extensive layer of botryoidal Pyromorphite formations. Most groups are round, some fused and all undamaged. The colour is pale green. In some areas well-formed individual crystals can be seen under magnification. Bright luster which shows up particulalry well under good illumination.

Location: Roughton Gill, Caldbeck Fells, Cumbria, England.