BALL CLAY is a variety of Kaolinite, like china-clay. It differs from china-clay in having high plasticity and less refractoriness. In chemical composition, Ball clays usually contain three dominant minerals: from 20-80% kaolinite, 10-25% mica, and 6-65% quartz. In addition, there are other ‘accessory’ minerals and some carbonaceous material (derived from ancient plants) present. The main utility of ball clay is its plasticity and it is mixed with non-plastic or less plastic clays to make them acquire the requisite plasticity. The high plasticity of ball clay is attributed to the fact that it is fine-grained and contains a small amount of montmorillonite.