The Occurrence of Tellurium and Bismuth in the Gold-Bearing Polymetallic Sulfide Ores in the Sudetes (Sw Poland)

This paper provides a detailed description of the geochemical and mineralogical characteristics of the occurrence of tellurium and bismuth in gold-bearing, polymetallic sulfide deposits and their prospects in the Sudetes Mountains (specifically in Z³otym Stok, Czarnów, Radzimowice,Radomicc, and Bardo Śląskie). Tellurium is classified as a critical element, and its role in modern industry is gradually increasing due to high demand for use in solar batteries and memory discs. Within the study area, the highest Te concentration (approx. 150 ppm) was determined in auriferous arsenic-chalcopyrite ores in Radzimowice, and the highest bismuth concentration (0.5%) in sulfide ores in the Czarnów deposit. In other studied areas, Te content ranges from a few up to dozens of ppm, and Bi from dozens up to hundreds of ppm. These concentrations are much higher than their Clarks in the earth’s crust. Among Teminerals in the Radzimowice and Czarnów deposit, Ag-tellurides (hessite) dominated, while Bi-tellurides (hedleyite and tellurobismuthite) prevailed in Bardo Śląskie. Tellurides occur mainly as micro-inserts in sulfides in paragenetic association with Au, Ag, and Bi minerals. Bi minerals were recognized in all of the studied deposits, represented mainly by native bismuth and a secondary Bi-mineral - bismuthinite. Tellurium and bismuth usually have a strong positive correlation (cc > 0.6) with Au, Ag, and Pb. Crystallization of tellurides occurred in at least two separate events of ore crystallization at temperatures ranging from 200 to 300°C. The first event dominated by Bi-tellurides was connected with metasomatic processes in the contact zones of Variscan granites (Czarnów and Bardo Śląskie), and the second event with Ag-tellurides was connected with epithermal low sulfidation processes related to Variscan porphyries (Radzimowice). Bi and Te played a significant role as scavengers of gold from hydrothermal fluids. These elements also have important metallogenic and prospecting significance.