1. Department of Geological Engineering, Faculty of Mining and Geology, VŠB – Technical University of Ostrava, 17. listopadu 15, 708 33 Poruba-Ostrava, Czech Republic
2. Department of Mineralogy and Petrology, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, 842 15, Bratislava, Slovakia
3. Department of Geological Sciences, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic