Acta Musei Moraviae

Tellurium-rich polybasite and associated minerals from Ruda near Rýmařov, Horní Město Ore District, Czech Republic

A mineralogical study of a museum sample of quartz gangue hosting a nest of galena, which was collected from area of a former mine exploiting iron ore at Ruda near Rýmařov (Horní Město Ore District, Jeseníky Mts., Czech Republic), showed the presence of polybasite in addition to galena, quartz and dolomiteankerite. Polybasite has not been reported from this ore district yet. Polybasite from Ruda site is characterized by elevated contents of Te (1.60–1.89 wt. %, corresponding to 0.28–0.33 apfu Te). Such a Te-enriched composition has not yet been reported from polybasites found in Czech Republic and it is also a rare composition worldwide. Together with a former find of sylvanite in the area of an iron-ore deposit at Skály near Rýmařov, it is the second occurrence of Te-bearing minerals in the Horní Město Ore District. The existing evidence suggests that Te is a more characteristic element for lithological environment of oxidic and silicate iron ores belonging to the Lahn-Dill type than to stratiform sulfidic ores in the Horní Město Ore District.