Other Definitions
stoneware (dict)
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StonewareStoneware is an impervious type of pottery distinguished primarily by its firing temperature (from about 1200°C to 1315°C). In essence, it is man-made stone. In contrast, earthenware is fired at lower temperatures and is not impervious to liquids. Porcelain, a type of stoneware developed in China, is distinguished by the type of clay used, kaolin, resulting in a pure white color. Kaolin, or China Clay, which occurs in various parts of the world, is often 95% free of impurities. It is also fired to a vitreous state, transforming the constituent silica to glass. Some porcelains bodies are translucent after firing. Firing a piece of pottery to too high a temperature will result in warping or melting. Vitreous clay bodies can be made at different temperatures ranges, but they are typically fired in the stoneware/porcelain range. Fired stoneware absorbs up to 5% moisture, porcelain up to 3%, and earthenware up to 10%. Earthenware, when moist, is typically not freeze resitant. Clay refers to minerals of a plastic quality formed primarily of alumina and silica. Potters refer to combinations of clays mixed with other materials as clay bodies. Different kinds of clay bodies are created by mixing additives, such as sand, fluxes, grog, temper, flint, spodumene, wollastonite, or additional silica, to modify natural clays. Natural clays are thereby altered to fire at specific temperatures. Darker clays often contain iron and other metal oxide impurities. The clay used for porcelain and white stoneware clay bodies do not contain these impurities. Glaze may be applied to pottery before a second firing at a different temperature, or a glaze may be applied before a single firing.
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