Platinum group metals ("PGMs") are rare precious metals, which frequently occur together in nature as constituents of various ores and minerals. PGMs are a family of six metals: platinum, palladium, rhodium, iridium, ruthenium, and osmium, all of which have similar chemical and physical properties and are grouped together in the periodic table. PGMs are regarded as strategic industrial metals because of their extensive use in the petrochemical, automotive and electronic industries. In many applications, it is impossible to substitute PGMs economically and technically.