Stoneware

Stoneware is a broad class of pottery fired at a relatively high temperature, to be impervious to water.^[2] A modern definition is a vitreous or semi-vitreous ceramic made primarily from stoneware clay or non-refractory fire clay.^[3][4] This definition excludes stone vessels that are carved from a solid chunk of stone. End applications of stoneware include tableware and decorative ware such as vases.

Stoneware is fired at between about 1,100 °C (2,010 °F) to 1,300 °C (2,370 °F). Historically, reaching such temperatures was a long-lasting challenge, and temperatures somewhat below these were used for a long time.^[5]

It was developed independently in different locations around the world, after earthenware and before porcelain. Stoneware is not recognised as a category in traditional East Asian terminology, and much Asian stoneware, such as Chinese Ding ware for example, is counted as porcelain by local definitions.^[6]: 22 Terms such as "porcellaneous" or "near-porcelain" may be used in such cases. Traditional East Asian thinking classifies pottery only into "low-fired" and "high-fired" wares, equating to earthenware and porcelain, without the intermediate European class of stoneware, and the many local types of stoneware were mostly classed as porcelain, though often not white and translucent.^{[6]: 22, 59–60, 72}

One definition of stoneware is from the Combined Nomenclature of the European Communities, a European industry standard. It states:

Stoneware, which, though dense, impermeable and hard enough to resist scratching by a steel point, differs from porcelain because it is more opaque, and normally only partially vitrified. It may be vitreous or semi-vitreous. It is usually coloured grey or brownish because of impurities in the clay used for its manufacture, and is normally glazed.^[4][7]