 stoneware is a vitreous or semi-vitreous ceramic made primarily from stoneware clay or non-refractory fire clay.standard terminology of ceramic whiteware and related products: astm standard c242. stoneware is fired at high temperatures. it is nonporous and so does not need a glaze. ==definition and description==   one widely-recognised definition 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."arthur dodd & david murfin. dictionary of ceramics; 3rd edition. the institute of minerals, 1994. the key raw material in stoneware is either naturally occurring stoneware clay or non-refractory fire clay. the mineral kaolinite is present but disordered, and although mica and quartz are present their particle size is very small. stoneware clay is often accompanied by impurities such as iron or carbon, giving it a "dirty" look, and its plasticity can vary widely.cuff, yvonne hutchinson. ceramic technology for potters and sculptors. london: a.&c. black, 1994, p. 64. non-refractory fire clay may be another key raw material. fire clays are generally considered refractory, because they withstand very high temperatures before melting or crumbling. refractory fire clays have a high concentration of the mineral kaolinite, with lesser amounts of mica and quartz. non-refractory fire clays, however, have larger amounts of mica and feldspar.cripss, j.c.; reeves, g.m.; and sims, i. clay materials used in construction. london: the geological society, 2006, p. 408. formulations for stoneware vary considerably, although the vast majority will conform to: plastic fire clays, 0 to 100 percent; ball clays, 0 to 15 percent; quartz, 0 to 30 percent; feldspar and chamotte, 0 to 15 percent.rhodes, daniel and hopper, robin. clay and glazes for the potter. iola, wisc.: krause publications, 2000, p. 109. stoneware can be once-fired or twice-fired. maximum firing temperatures can vary significantly, from 1100&nbsp;Â°c to 1300&nbsp;Â°c depending on the flux 
Ceramic_materials Cookware_and_bakeware Pottery Stoneware Tableware