Earthenware is glazed or unglazed nonvitreous pottery that has normally been fired below 1200°C. Porcelain, bone china and stoneware, all fired at high enough temperatures to vitrify, are the main other important types of pottery. Earthenware comprises most building bricks, nearly all European pottery up to the seventeenth century, most of the wares of Egypt, Persia and the near East; Greek, Roman and Mediterranean, and some of the Chinese; and the fine earthenware which forms the greater part of our tableware today. Pit fired earthenware dates back to as early as 29,000–25,000 BC, and for millennia, only earthenware pottery was made, with stoneware gradually developing some 5,000 years ago, but then apparently disappearing for a few thousand years. Outside East Asia, porcelain was manufactured only from the 18th century AD, and then initially as an expensive luxury. After it is fired, earthenware is opaque and non-vitreous, soft and capable of being scratched with a knife. The Combined Nomenclature of the European Communities describes it as being made of selected clays sometimes mixed with feldspars and varying amounts of other minerals, and white or light-colored (i.e., slightly greyish, cream, or ivory).
UNESCO page: [1]