Abstract Clay minerals are used for many purposes. One of the most versatile clays is kaolin, which is found in many products including paper, paint, plastics, rubber, ceramics, fiberglass, cosmetics, cement, various construction materials, ink, and pharmaceuticals. Kaolin is suitable for such a diverse range of applications because of its low cost, platy morphology, naturally fine-particle size, consistent chemical composition, superior optical properties and excellent flow characteristics when dispersed as slurry. Most of the world's supply of high-grade kaolin is mined from extensive sedimentary deposits located in the southeastern United States and the eastern Amazon basin of Brazil. Another important source of high-grade kaolin is the primary kaolin deposits located in Cornwall, England. In Georgia, which supplies approximately 70% of the world's high-grade kaolin, two types of sedimentary kaolin are mined for three major markets. The two types are soft kaolin and hard kaolin. Soft and hard kaolins are significantly different in terms of mineralogy, particle shape and size, chemistry, and physical properties. Consequently, each type is used in different applications. The three most important end-use markets for kaolin mined in Georgia are 1) paper (filler and coating), 2) ceramics (sanitaryware and dinnerware), and 3) fiberglass. Each end-use requires different kaolin properties, and these properties are controlled by the mineralogy of the crude kaolin.