Stoneware China

Stoneware is so named because of its dense stone-like character which is waterproof and opaque. It is naturally gray, then turns light brown or buff during the firing process. Glazes in various colors may be applied after firing at temperatures between 1100 and 1300 degrees Celsius. Stoneware differs from porcelain because it is much more opaque and only partially vitrified, a process that transfers a substance into glass. The main material in stoneware is either naturally occurring clay or non-refractory fire clay. Small amounts of various minerals such as mica and quartz are also present.

Stoneware production can be traced back as early as the Shang Dynasty in China around 1400 B.C. It was not until the 15th century that it appeared in Europe. In 1768, Josiah Wedgwood created black stoneware known as Black Stonewood made from reddish-brown clay that turned black after the firing process. A richer color was obtained by adding manganese. Black Stonewood was so successful and superior in appearance that Wedgwood still creates ornamental pieces using this process.

Stoneware production was extremely popular in 19th century North America and was the primary material for many houseware items. Salt glaze is the typical glaze technique seen on American stoneware, followed by various decorating techniques. Stoneware was so valued in America because of its lead-free production, as opposed to the lead-glazed earthenware that was so popular beforehand.

Quick Facts

• The term "crock" is sometimes used to refer to American stoneware
• Stoneware clays are preferred by manufacturers and artists creating pottery
• An O-Meibutsu stoneware tea leaf storage jar from the 13th-14th century was sold at Christie's New York in September 2009 for $662,500