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Crystals of platinum-group minerals from the Konder massif, located near Nel'kan in the Russian Far East, were examined by optical microscopy, X-ray diffraction, scanning electron microscopy, and by electron probe microanalysis. They were found to be ferroan platinum (Pt^sub 3^Fe) and platinum-bearing zvyagintsevite (ideally Pd^sub 3^Pb). Several other species were found in association, including cooperite (PtS), hongshte (?) (PtCu), palladian-cuprian electrum and gold.
INTRODUCTION
Mr. Brad van Scriver, Heliodor, PO. Box 10, 19900 Prague 9, Czech Republic, approached CANMET with a request for a mineralogical characterization of three "platinum crystals" from the Russian Far East. These crystals are similar to some previously illustrated in mineralogical journals in color photomicrographs (e.g., Mineralogical Record, 24, 225 and 26, 529). Mr. van Scriver wished to confirm that the crystals he had bought in good faith are genuine minerals. He had been given limited information about the locality and the geology, ". . a pipe in an old river bed . . ," which "The Russians claim is an alluvial prospect, but some of the xls are so sharp they seem not to have been moved at all (elluvial?)." The location on a label as given was "Konder (Village), near Nelkan, Ajano-Maiskiv region, Khabarovskiy Kray, Russia, C.I.S." Mr. van Scriver also supplied crystals of a possible palladium mineral from the same locality.
When this investigation was begun, we had little information on the locality or on Russian publications describing the locality and its mineralogy. We have subsequently been fortunate to have not only obtained several relevant Russian publications, but also to have made direct contact with Russian geologists who have worked on the Konder' massif.
The Konder massif is a circular, concentrically zoned alkaliultramafic massif with a diameter of about 7 km, situated in the Ayan-Maya region in the northern part of Khabarovsk Territory, about 200 km west of the Sea of Okhotsk, Far Eastern Russia (Makrushev et at., 1990; Nekrasov et al., 1994). It is one of several concentric ultramafic massifs that intruded the Archean and Proterozoic rocks of the Siberian Platform (Aldan Shield) as shown in Figure 1. It had been classified as an Inagli (Aldan) type of intrusion, a sub-type of forsteritic dunites intruded into stable platforms at shallow depths (Razin, 1976; Cabri and Naldrett,...