1. Mineralogy
Department, Institute for Geosciences, Friedrich-Schiller University Jena, Carl-Zeiss-Promenade 10, Jena, Germany
2. Department
of Mineralogy and Petrography, Natural History Museum, Burgring 7, A-1010 Vienna, Austria
3. Institute
of Mineralogy and Crystallography, University of Vienna, Althanstraße
14, A-1090 Vienna, Austria