High-fired stoneware

Ceramics can be classified by considering the firing temperature and the resulting porosity thus high-fired stoneware (produced at above 1000°C) has porosities less than 2% and low-fired earthenware (firing between 600 and 900°C) with far more than 10% porosity are at the upper and lower ends of the scale. Porcelain (defined as white and translucent ceramic, fired up to 1400°C) can exhibit an extremely low porosity, whereas terracotta or raku (both fired below 1000°C) would be examples of high porosity. 

In the Shang Dynasty, the first example of potteiy covered with a high-fired feldspathic glaze [2] was observed. The body of this vase, shown in Figure 1.6, is of near stoneware hardness. The aze, requiring kiln temperatures of 1200°C, is spread uniformly over the whole body. This aze technology then disappears from the archaeological record until the late fourth or early third centuiy B.C. 

Bright yellow-white Mid-range clays and low-fire stonewares mature. High... 

Ceramics are inorganic solids, usually oxides, which contain ionic and covalent bonds. The material, formed by sintering at high temperatures, ranges from amorphous glass-like material to highly crystalline solids, from insulators to conductors or semiconductors. They include earthenware, which is fired at 1,100-1,300 K and a porosity of about 8% fine china or bone china, fired at 1,400-1,500 K with a porosity of less than 1% stoneware, fired at over 1,500 K with a porosity of about 1% before glazing and porcelain which is fired at over 1,600 K and has a much finer microstructure than either stoneware or bone china. 

---