Form of presence of gold in porphiry copper deposit Buchim (Eastern Macedonia)

Tho investigations and examinations done so far determined that the distribuiton of gold in the deposit is in close correlation to that of the copper, where gold most often occurs as native (hosted mainly in the chalcopyrites, par tially in pyrites and rarely in the magnetites) and in the form of gold tellurides (calaverite and krennerite). The latest ore microscope examinations and analyses of the elec­ tronic microprobe determined that in Buchim deposit, bisides the determined mineralogical forms of presence of go ld, electrum and petzite also appear, which at the same time, represent new mineral kinds for the mineral association in t his deposit , At the same time the distribution of Au and Ag in t he electrum and the variations of Au in individual parts (central bnd rim) of the larger grains of the native gold was followed. and it was det ermined that the contents of Au and Ag in the electrum are close to the standard , while the Au contents in the native gold are variable and range within 80 - 92 % Au