The platinum-group elements (PGE) include platinum, palladium, rhodium, ruthenium, iridium and osmium. They are currently receiving world-wide attention as an attractive exploration target because they offer the dual attraction of rare, high value precious metals as well as major industrial applications. Platinum has aesthetic qualities, combined with a permanent lustre, which encourage its use in the manufacture of jewellery and, like gold, it also finds an investment role. Platinum, rhodium and palladium have important applications as catalysts, enabling petroleum and other fuels and chemicals to be produced efficiently from crude oil. This book gives a practical set of guidelines for implementing a programme of PGE exploration, detecting subtle indications of mineralization and assessing the economic potential of a group of mafic or ultramafic rocks. Background material is given on the economic and geological framework of the PGE in the first chapter, while theoretical aspects of magma chemistry are covered in the next three.