PLUMBOGUMMITE PSEUDOMORPH AFTER PYROMORPHITE, SYLVESTER MINE, ZEEHAN DSTR TASMANIA

Plumbogummite is a rare mineral that falls under the category of secondary lead phosphate minerals and is part of the alunite supergroup, specifically the crandallite subgroup. This subgroup includes other minerals like crandallite, where calcium takes the place of lead, and goyazite, which has strontium instead of lead. Another member is philipsbornite, where the arsenate group replaces the phosphate group. Plumbogummite was first identified in 1819 and received its name in 1832, derived from the Latin words "plumbum," meaning lead, and "gummi," referring to gum, due to its lead content and its sometimes gum-like appearance.

Pyromorphite is a mineral consisting of lead chlorophosphate, represented by the formula Pb5(PO4)3Cl, and can be found in sufficient quantities to be extracted as a lead ore. It typically forms crystals that exhibit a hexagonal prism shape, often capped with basal planes and occasionally featuring narrow hexagonal pyramid faces. Barrel-shaped crystals are also relatively common, along with globular and reniform aggregates. As a member of the apatite mineral group, pyromorphite closely resembles mimetite (Pb5(AsO4)3Cl) and vanadinite (Pb5(VO4)3Cl) in both physical and chemical properties, making it challenging to differentiate among them without chemical analysis.