Ceramics is a general term for pottery and porcelain. People invented pottery as early as the Neolithic Age about 8,000 years ago. Common ceramic materials include clay, alumina and kaolin. Ceramic materials are generally hard but less malleable. Ceramic materials are made by quenching clay, which is a large original resource of the earth. The nature of clay with toughness, room temperature water can be molded, slightly dry can be carved, all dry can be ground; burned to 700 degrees can be made into pottery can be filled with water; burned to 1230 degrees is porcelain, can be almost completely non-absorbent and corrosion-resistant and heat-resistant. Ceramic materials are mostly oxides, nitrides, borides and carbides.
