Abstract:
Three types of oxidized ores in Ik-Davlyat gold-polymetallic deposit (South Urals) arc characterized from mincralogical points: 1) carbonate-sericite-chlorite mineralized rocks, 2) vein-shaped quartz-goethitc-illite clays, and 3) limonitized rocks connected with veins. Heavy concentrate of the first ore type is composed mainly of go-cthite and rutile and contains native gold Auo.9iAgo.osCuo.oi <http:> and chalcophanite Zn1.02Mn2.9gO4 <http:> ■ ЗН2О. The concentrate of the second ore type, consisting of gocthitc, rutile and lead-bearing jarositc, contains native gold Auo.90-o.93Ago.06-o.08Cuo_o.01Feo_o.ob <http:> silver amalgamidc (schachnerite) Ago.75Hgo.97Auo.98 <http:>-Ago.75Hgo.97Auo.28 <http:>, coronaditc (PbujM^.siFco./iiCuojeJsO^, chalcophanite-hydrohctaerolitc mixture, and ccrussite. Gold with the highest fineness (Auo.9gAgo.01Cuo.01 <http:>) associates with silver amalgamidc. The third type ore is quite similar to the first one, but includes an admixture of jarositc. The composition of oxidized ores indicates to difference in composition of the primary ores, for instance, to presence of lead minerals in the veins. The finding of chalcophanite is the first one in Russia, it is confirmed by chemical, optical and X-ray analyses.