BORNIT Z HYDROTERMÁLNÍ MINERALIZACE HISTORICKÉHO LOŽISKA ZLATÝ DŮL U HLUBOČEK (KULM NÍZKÉHO JESENÍKU)
Secondary bornite occurs within quartz-carbonate ore vein in dump material at historical deposit of Zlatý důl near Hlubočky. This mineral was characterized using ore microscopy and electron microprobe analyses. The studied sample was formed by quartz, which occurs in the centre of the ore vein, carbonate of the dolomite-ankerite series, which formed bands on the edge of the ore vein and the unspecified beige coloured carbonate. The ore minerals were represented by primary chalcopyrite and secondary chalcocite, covellite and galena (the layer of galena grows on chalcocite on the edge of the altered chalcopyrite aggregate). The studied sample was partly weather-worn and especially carbonate of the dolomite-ankerite series was altered to iron oxyhydroxides. Bornite lamellae up to 100 × 40 μm were found along cracks of the chalcopyrite aggregate (where chalcopyrite is altered to chalcocite). Lamellar bornite occurs also in secondary chalcocite. Bornite contained only trace amount of Pb, other elements (Zn, Co, Ni, Mn, Cd, Hg, As, Ag, Bi, Sb, Se and Cl) were bellow the detection limits. Bornite is probably a secondary mineral, which was formed at the expense of chalcopyrite. Bornite from historical deposit of Zlatý důl represents the first occurrence of this mineral in the Bystřice Ore District and also in the whole Moravo-Silesian Culm.