A very interesting specimen, of black sphalerite – marmatite and chalcopyrite, overgrowth by large galena cubic crystals, followed by flat rhombohedral calcite crystals. In the late stage of crystallization, galena was strongly dissolved and some of the crystals are particularly destroyed. Could be seen typical „fingerprint“ dissolution, but the surfaces stay mirror lustrous. Probably the same process was the reason for appearance of „rainbow chalcopyrite surfaces“ – the result of the coating by bornite and covellite.
size 110 x 65 x 50 mm – weight 311,7 grams