Rare Mineral Phases Related with Major Sulphide Minerals in the Bučim Porphyry Copper Deposit, R. Macedonia

Abstract

With the latest detailed mineralogical studies with polarizing optical microscope and microprobe analysis in the Bučim porphyry copper deposit were found and determined several representative and rare mineral phases, which have been composed metals from the gold-platinum group as well as those from the Cu-Bi-Se-Te-As group. In the bismuth-selenium of rare mineral phases were confirmed bismuthinite, galenobismutite, krupkaite, frie­drichite, emplectite, laitakarite and native bismuth, which represent new rare mineral phases in the Bučim porphyry copper deposit, as well as mineral phases of the Au-Pd group where clearly was confirmed presence of gold and pal­ladium with elemental mixtures representative for these mineral phases. It should be stressed out that both types of rare mineral phases were determined in pyrite and chalcopyrite from major ore parageneses in the Bučim deposit. The bismuth-selenium mineral phases are related to the major quartz-pyrite-chalcopyrite paragenesis, while Au-Pd mineral phases are related with slightly higher temperature, oxido-sulphide parageneses such are magnetite-pyrite-chalcopyrite (Mt-Py-Cp) and pyrite-chalcopyrite (Py-Cp).