Throughout the earliest traditions of civilization till our days pottery reflects large range of human creativity: functional, sculptural and abstract forms of expressions. The material that potters use is clay, an extremely common and abundant substance in natureĀ—a nuisance to farmers and gardeners but a joy to potters. Clay is a product of continuous geological weathering of the surface of earth. It is one of the abundant components that makes up the surface of the planet. So, not to worry: potters can never exhaust this continuously produced reserve of clay! The chemical formula of clay is , and its mineralogical name is Kaolinite. However, the formula does not give account to numerous impurities such as other minerals in the clay. Approximate density of Kaolinite is 2.6 . This and other similar minerals that make up for clays are difficult to differentiate from each other and the techniques for doing so include X-ray spectroscopy and electron microscopy. More information on kinds of clay, mining and preparing clays as well as on preparation of glazes from abundantly naturally occurring inorganic materials, and other interesting topics in pottery can be obtained by reading D. Rhodes' book, ``Clay and Glazes for the Potter", 2000, Krause Publications, Iola, WI, United States.