Results of selected projects on Exploration R & D, one of the major research areas implemented by the Commission of European Communities in Brussels on the subject of mineral raw materials, are presented on an international basis. All aspects of the geology and geochemistry of ore deposits and their host rocks are covered. Main headings are according to commodity, i.e. tungsten, chromite, and base metals, rather than by scientific criteria. The scope and subject matter varies from the metallogenic province to the individual deposit. The question of possible application to exploration methodology is explored in several papers. Particularly structural and geochemical techniques are discussed.