Pyromorphite, Pb5(PO4)3Cl is a secondary mineral of lead sulphide, Pb5 This specimen is from an open cut near the upper Mexico mine, Caldbeck fells, in Cumbria, and is composed of very short, apple green, prismatic crystals. The crystals are arranged in laterally orientated connecting chains. The crystals are well defined, but quite stubby, unlike the elongated barrel type crystals from the mines of central Wales. All faces of the specimen have a little evidence of pyromorphite, but this face is by far the best populated