“…In the earth, abrasion of minerals is one of the principal weathering processes in dry regions. Many papers report on the effect grinding of clay minerals, such as kaolinite (Stepkowska et al, 2001;Horváth et al, 2003;Makó et al, 2006;Leonel et al, 2014;Shahverdi-Shahraki et al, 2015) and smectite (Volzone et al, 1987;Volzone and Sanchéz, 1993;Sanchéz, 1997;Christidis et al, 2005;Hrachová et al, 2007), on their structure, crystallinity, and properties. For example, it causes the increase of surface area in first stages of grinding, and its decrease with further grinding because particles are stuck one to another.…”