The First Finds of Rhenium Minerals in Karelia

摘要

Rhenium is one of the rarest elements of the earth crust (abundance ratio 0.7 mg/t). In the Karelian region, Re and accompanying Os were discovered in a copper-molybdenum-porphyry ore formation, represented by the Lobash deposit, the Jalonvaara occurrences etc., and in a noble-metal-Cu-U-vanadium ore formation (Padma Group occurrences). Molybdenites from the above deposits are enriched in Re and Os (Lobash: 13-187 g/t Re, 0.4-6 g/t Os). So far, however, no rhenium minerals proper have been revealed in the Karelian deposits and occurrences of the above formations or elsewhere. As a result of the microprobe study of mineral assemblages of cupreous sandstones from the Voronov Bor deposit (bornite ore) and sulphide-copper-nickel ore from the Rybozero deposit, osmium-cupreous rheniite (Re, Cu, Os, Fe)_1S_2 that contains 56.53-60.25% Re, 4.61-10.99% Cu, 1.52-3.77% Os and up to 4.75% Fe was revealed and studied for the first time.