Porcelain is a hard ceramic substance made by heating at high temperature selected and refined materials often including clay in the form of kaolinite. Porcelain clay when mixed with water forms a plastic paste which can be worked to a required shape or form that is hardened and made permanent by firing in a kiln at temperatures of between about 1200 degrees Celsius and about 1400 degrees Celsius.
The toughness, strength and translucence of porcelain arises mainly from the formation at high temperatures within the clay body of the mineral mullite and glass. Porcelain was so-named after its resemblance to the white, shiny Venus-shell, called in old Italian porcella. The curved shape of the upper surface of the Venus-shell resembles the curve of a pig’s back (Latin porcella, a little pig, a pig).
Properties associated with porcelain include those of low permeability, high strength, hardness, glassiness, 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. Porcelain is used to make wares for the table and kitchen, sanitary wares, decorative wares and objects of fine art. Its high resistance to the passage of electricity makes porcelain an ideal insulating material and it is used in dentistry to make false teeth, caps and crowns.
The earliest porcelains originated in China possibly during the Eastern Han dynasty (25-220 AD). The reader is referred to the Wikipedia article on Chinese porcelain for a discussion on the early history of the material and its modern uses in Chinese craftmanship and pottery.