Anglesite Leadhills, in Scotland, pseudomorphs of anglesite after galena are known. At most localities it is found as isolated crystals in the lead-bearing lodes, but at some places, in Australia and Mexico, it occurs as large masses, and is then mined as an ore of lead. Anglesite is sometimes used as a gemstone. Lead(II) sulfate Anglesite Anglesite is a lead sulfate mineral with the chemical formula PbSO. It occurs as an oxidation product of primary lead sulfide ore, galena. Anglesite occurs as prismatic orthorhombic crystals and earthy masses, and is isomorphous with barite and celestine. It contains 74% of lead by
Mineral ore of zinc, or cassiterite (SnO), an ore of tin. Gems are minerals with an ornamental value, and are distinguished from non-gems by their beauty, durability, and usually, rarity. There are about 20 mineral species that qualify as gem minerals, which constitute about 35 of the most common gemstones. Gem minerals are often present in several varieties, and so one mineral can account for several different gemstones; for example, ruby and sapphire are both corundum, AlO. Minerals are classified by variety, species, series and group, in order of increasing generality. The basic level of definition is that of mineral species,