1. Faculty of Science; Institute of Geochemistry, Mineralogy and Mineral Resources; Charles University in Prague; Albertov 6 128 43 Prague 2 Czech Republic
2. Population Protection Institute; Na Lužci 204 533 41 Lázně Bohdaneč Czech Republic
3. Independent gemmologist; Vysoký Újezd 161 267 16 Vysoký Újezd Czech Republic
4. Department of Dosimetry and Application of Ionizing Radiation; Faculty of Nuclear Sciences and Physical Engineering; Czech Technical University in Prague; Břehová 7 115 19 Prague 1 Czech Republic