Mineral Species: Pyromorphite
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 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: Granular crystals of green Pyromorphite on a matrix of Quartz. The deposit of Pyromorphite is very rich and under magnification shows small spherical aggregates. The Quartz is extremely well-formed and consists of transparent pyramidal crystals. An outstanding combination.
Location: Bwlch-glas Mine, Tal-y-bont, Ceredigion, Wales.
