Michal Filippi Michal Filippi earned his Ph.D. in environmental mineralogy from the Charles University in Prague, in 2007. He is now a research worker at the Institute of Geology of Czech Academy of Science, v.v.i. in Prague, Czech Republic. He has two main research interests. One focuses on mineralogical speciation of the arsenic in the environment, especially in different mine wastes and in naturally contaminated soils. The second interest focuses on evolution of salt karst areas and on karst mineralogy in general.