Výskyt tetradymitu a telurobizmutitu pri Pukanci, Štiavnické vrchy (Slovenská republika).

Bismuth tellurides (tetradymite and tellurobismuthite) were identified in the heavy mineral fraction of alluvial placers from Pukanský potok brook near Pukanec, Štiavnické vrchy Mountains, Slovak Republic. They forms only very slightly rounded aggregates up to 5 mm in size with typical perfect cleavage. Aggregates of bismuth tellurides from Pukanec are mostly represented by tetradymite, which has an uniform chemical composition and only minor contents of Se (up to 0.10 apfu) and Sb (0.01 apfu) were detected. Its empirical formula is (Bi2.00Sb0.01)Σ2.01Te1.99(S0.92Se0.08) Σ 1.00 on basis of 5 apfu. Tellurobismuthite was observed as microscopic oval or irregular elongated inclusions in tetradymite. Only rarely aggregates of tellurobismuthite up to 3 mm in size with thin tetradymite rim were observed. The chemical composition of tellurobismuthite is nearly close to the end member, it has only minor contents of Se (0.02 apfu) and Sb (0.02 apfu) and its empirical formula is (Bi2.01Sb0.02)Σ2.03(Te2.96Se0.01)Σ2.97 on basis of 5 apfu. This find of bismuth tellurides indicates the existence of previously unknown primary Bi-Te mineralization near Pukanec, but its connection to the epithermal Au-Ag mineralization is not clear. [ABSTRACT FROM AUTHOR]