Galena's the natural mineral form of lead sulfide. It's the most important lead ore mineral. Galena's one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms. It's often associated with the minerals sphalerite, calcite and fluorite. Lead ore deposits Galena deposits often contain significant amounts of silver as included silver sulfide mineral phases or as limited solid solution within the galena structure. Th… (More on Galena)