This chapter contains sections titled: Ru Facts about Ruthenium Rh Facts about Rhodium Pd Facts about Palladium Os Facts about Osmium Ir Facts about Iridium Pt Facts about Platinum The Platinum Group Metals – PGMs – An Overview Discovery of Natural Platinum A Stranger Among the Hieroglyphs Platinum in the Old World Platinum in South America Platinum and the Form of the Earth Platinum in Europe The Discovery of Platinum Metals in Platinum Tennant and Wollaston Osmium and Iridium Palladium and Rhodium Ruthenium Malleable Platinum Occurrence of the Platinum Group Metals The Geology Platinum Group Metals – Reserves Production of Platinum-group Metals (PGMs) Mining Enrichment of the PGMs Separating Platinum, Palladium, Iridium, Osmium, Rhodium and Ruthenium Quantities of Platinum, Palladium and other PGMs Produced Uses of the Platinum Group Metals An Overview Platinum Palladium Rhodium Iridium Osmium Ruthenium The Varying Value of Platinum Metals Biological Roles of Metals in the Platinum Group