Moijabana rocks-Pilikwe pots: The acceleration of clay formation by potters employing simple mechanical means

Throughout the history of potting in Botswana, from about CE200 to the present, potters have used a variety of clays. Alluvial clays are favored by most potters today, but petrographic analyses show that prehistoric potters preferred primary clays directly derived from granite and basalt. Fortunately, a few potters in the region today still use granite-derived clays. We trace the processes by which potters of Pilikwe village mine weathered granite from a source at Moijabana and transform it through a series of crushing, pounding, sifting, and wetting actions into a paste that can be used the following day to form pots. These mechanical operations accelerate natural rock weathering processes that form clays and in a single day achieve what in nature takes thousands of years. Successive stages of clay collection and processing were observed, recorded, and filmed; samples from each stage were subsequently analyzed by thin-section optical petrography. Fabrics of pots made from this processed clay were analyzed by identical means and compared with the raw materials.