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Pottery is the ceramic ware made by potters. In everyday usage the term is taken to encompass a wide range of ceramics, including earthenware, stoneware, and porcelain. The places where such wares are made are called potteries.
Pottery is made by forming a clay body into objects of a required shape and heating them to high temperatures in a kiln to induce reactions that lead to permanent changes, including increasing their strength and hardening and setting their shape. There are wide regional variations in the properties of clays used by potters and this often helps to produce wares that are unique in character to a locality. It is common for clays and other minerals to be mixed to produce clay bodies suited to specific purposes; for example, a clay body that remains slightly porous after firing is often used for making earthenware or terra cotta flower-pots.
Porcelain was named after its resemblance to the white, shiny cowry, called in old Italian porcella (little pig), because the curved shape of its upper surface resembles the curve of a pig's back. Properties associated with porcelain include low permeability, high strength, hardness, glassiness, high durability, whiteness, translucence, resonance, brittleness, high resistance to the passage of electricity, high resistance to chemical attack, high resistance to thermal shock and high elasticity.
For the purposes of trade, the Combined Nomenclature of the European Communities defines porcelain as being "completely vitrified, hard, impermeable (even before glazing), white or artificially coloured, translucent (except when of considerable thickness) and resonant." However, the term porcelain lacks a universally agreed definition and has "been applied in a very unsystematic fashion to substances of diverse kinds which have only certain surface-qualities in common" (Burton 1906).
Porcelain is used to make table, kitchen, sanitary and decorative wares, objects of fine art and tiles. Its high resistance to the passage of electricity makes porcelain an excellent insulating material and it is widely used for high-voltage insulators. It is also used in dentistry to make false teeth, caps and crowns.