1. Department of Structure Analysis, Institute of Physics, Czech Academy of Sciences, Na Slovance 1999/2, Prague 8, 182 21, Czech Republic
2. Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic
3. Institute of Geochemistry, Mineralogy and Mineral Resources, Charles University in Prague, Faculty of Science, Albertov 6, 128 43 Prague 2, Czech Republic