Brief Description: Plinius uses the term galena to describe lead ore. Galenite has the chemical formula PbS and it belongs to the category Sulphurus Minerals. Its colour is lead grey and it has metallic lustre that slightly dims when exposed to air. It is opaque and has specific gravity 7.5 with hardness 2½ and fusibility 2. Its crystals are cubic or cubic-octahedral. It is often found in schistose aggregates, rough-grained, fine-grained to solid. It alters into cerussite, anglesite, pyromorphite, mimetite. It occurs in hydrothermal veins together with sphalerite, iron pyrite, marcasite, chalcopyrite, cerussite, anglesite, dolomite, calcite, quartz, barite, fluorite. It constitutes the only source of lead, while it is a very important silver ore. 
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