Crystallite size distribution of clay minerals from selected Serbian clay deposits

Abstract

The BWA (Bertaut-Warren-Averbach) technique for the measurement of the mean crystallite thick- ness and thickness distributions of phyllosilicates was applied to a set of kaolin and bentonite minerals. Six samples of kaolinitic clays, one sample of halloysite, and five bentonite samples from selected Serbian deposits were analyzed. These clays are of sedimentary, volcano-sedimentary (diagenetic), and hydrothermal origin. Two different types of shape of thickness distribution were found - lognormal, typical for bentonite and halloysite, and polymodal, typical for kaolinite. The mean crystallite thickness (T BWA ) seams to be influenced by the genet- ic type of the clay sample.