Acta Musei Moraviae

Iron-rich zeolites from the locality Svojanov, Czech Republic

Svojanov locality is situated in Pardubice region (Czech Republic), about 15 km SE far from Polička town, in a closed quarry located on NW of Svojanov village nearby Svojanov-Rohozná road. High contents of Fe were found by an electron microprobe in zeolites from the locality Svojanov. In the examined sample, free zeolites – ferrierite-Mg, chabazite-Ca and clinoptilolite-Mg, were identified closely associated with chlorite and calcite. Ferrierite-Mg crystals are radialized into red to brown spherulitic agregates. Chabazite-Ca and clinoptilolite-Mg were present only in a microscopic size in the examined sample. Chabazite-Ca is the rdest whereas clinoptilolite-Mg is probably the youngest zeolite. Ferrierite-Mg is the Fe-richest (1.40–2.10 apfu; 1.87–2.77 wt. % Fe₂O₃), there is less Fe³⁺ in chabazite-Ca (0.03–0.14 apfu; 0.14–0.57 wt. % Fe₂O₃) and clinoptilolite-Mg (0.37–0.38 apfu; 0.51–0.52 wt. % Fe₂O₃), but the amount of Fe³⁺ is still significant within the zeolite group. There is a quite significant amount of Mg in ferrierite-Mg and clinoptilolite-Mg. The content of Mg in ferrierite-Mg (2.95–3.64 apfu; 4.76–6.00 wt. % MgO) is one of the highest in the world. The mineral association in studied sample from Svojanov is unique within the Czech Republic due to high amount of Fe³⁺ and Mg in zeolites.