Au-Pd bearing pyrites and chalcopyrites from the Buchim porphyry copper deposit, Eastern Macedonia

Interesting chemical compositions have been determined from the study of pyrite and chalcopyrite samples from the active Buchim open pit mine. Namely, beside the standard Fe, S, and Cu, increased concentrations of gold and palladium always followed by some amounts of arsenic were determined. In all the analysed pyrites, gold concentrations were within the range 0.027÷7.746% while the palladium concentrations were within the range 0.010–6.784%. Gold concentrations in all analysed chalcopyrites were within the range 0.009–9.095% while the palladium concentrations were within the range 0.020–8.110%. It is evident that concentrations of gold and palladium in the studied pyrite and chalcopyrite are almost always accompanied by increased concentrations of arsenic in the range of 0.002–0.761%. Increased gold and palladium concentrations have been determined in particular phases, especially in pyrite; in chalcopyrite they are due to metal substitution in the mineral lattice