clay (ceramics)

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Fine-grained sediment (mud) used as the basic material in ceramics. The term can refer to a variety of mixtures and textures. When moistened and wet, clay is plastic (flexible) and easily moulded. When dry, it becomes brittle and can crumble; if heated at high temperatures in a kiln, clay becomes very hard or ceramic (cannot be recycled with water). Clay may be white, grey, red, yellow, blue, or black, depending on its mineral composition. The most common types of clay are earthenware and terracotta; stoneware, with feldspar and a high silica content; porcelain clay, also known as kaolin or china clay; and bone china, a mixture of bone ash and kaolin. Other types of clay include raku, black clay, and Egyptian clay. In ceramics, clay type will often dictate final form.

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