Acta Musei Moraviae

Minerals of the jarosite group from sulphide-bearing assemblages on the eastern margin of the Bohemian Massif

The article is devoted to the study of the jarosite group minerals from supergene zone of various sulphidebearing assemblages (polymetalic Pb–Zn ores, pyrite-graphite rocks), emerging in connection with mining activities at the eastern margin of the Bohemian Massif. The most common species on the studied localities were jarosite (K = 0.50–0.88 apfu, Fe³⁺ = 2.63–3.00 apfu), whereas hydroniumjarosite (H₃O = 0.55–0.76 apfu, Fe³⁺ = 2.82–3.00) and plumbojarosite (Pb²⁺ = 0.35–0.48 apfu, Fe³⁺ = 2.64–2.92 apfu) are a less extended. Both Al- and P-bearing jarosites occur in locality Utín near Havlíčkův Brod. The proportions of individual end-members of the jarosite family varies in dependence on the temperature, pH, buffering capacity of the country rocks, and on availability of jarosite-forming elements (K⁺, Na⁺, Pb²⁺, Fe³⁺, SO₄^2-).