Results of ontogenetic studies of the early paragenesis of ore minerals in zonal clinopyroxenitedunite massifes of the Middle Urals are discussed. It is shown that the formation of these minerals occurs in the following order: iridosmium → chrome-spinel → laurite-erlichmanite → osmiridium → isoferroplatinum. Revealed ontogenic features of ore phases are in good agreement with models suggesting the concentration of platinum group metals at the magmatic stage of evolution of the clinopyroxenite-dunite massif before display of the superimposed high-temperature plastic deformation.