Zeunerite: The Rare Lead Phosphate Mineral

Zeunerite is a rare mineral, with the chemical formula Pb3(PO4)2. It is a lead phosphate mineral that was first described in 1869 from the type locality of the Zeune Mine, in the Harz Mountains of Germany. It is a member of the autunite group of minerals, which are all lead phosphates with the general formula Pb3(PO4)2x[H2O]y.
Zeunerite crystallizes in the monoclinic crystal system and typically forms as a pseudomorph after other minerals, such as galena or sphalerite. It is usually found in the oxidized zones of lead-zinc deposits, and less commonly in pegmatites and hydrothermal veins. It is a soft, brittle mineral with a Mohs hardness of around 2.5 to 3, and it has a vitreous luster.
Zeunerite is a relatively rare mineral, and it is not well known outside of the mineral collecting community. However, it is an interesting mineral for collectors because of its unique crystal form and its association with other lead phosphate minerals.