EN
Mineralogical composition and properties of acid and very acid weathered materials (upper-chalk clay, clay from sandstone interstick, tertiary clay, weathered of gneiss) as well as materials of neutral and alkaline pH (weathered of granite, basalt, serpentinite and cristalic limestone) occured in the Sudety Mountains. were analyzed. The analyzed materials of pH neutral and alkaline composed of illite. smektite and chlorite-talcite charakterize 1.5 - 5 time higher sorption capacity than materials of acid and very acid reaction. Mineralogical composition of clay minerals is a result of chemical properties of weathered rock and in older materials is a result of epigenetic processes.