Crystals of platinum group minerals (PGMs) of the Os–Ir–Ru and Pt–Fe systems from placer deposits of the South Urals are zonal and relatively homogenous in composition and can contain inclusions of PGE sulfdes, arsenides, sulfarsenides, and antimonides. The crystals are characterized by idiomorphic, compromise growth, and shear surfaces. Compromise growth surface of the PGM crystals with rock-forming minerals is evidence of their simultaneous crystallization in primary magma.

Figures 6. Tables 2. References 6.

Key words: platinum group minerals, ruthenium, osmium, iridium, crystal morphology, South Urals.

V.V. Zaykov, Institute of Mineralogy UB RAS, Miass, zaykov@mineralogy.ru

V.A. Popov, Institute of Mineralogy UB RAS, Miass;

E.V. Zaykova, Institute of Mineralogy UB RAS, Miass;

I.A. Blinov, Institute of Mineralogy UB RAS, Miass;

V.A. Kotlyarov, Institute of Mineralogy UB RAS, Miass

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