According to written accounts confirmed by archaeological finds, imported Chinese ceramics were widely available throughout the Abbasid period (749–1055). Potters in Iraq and Iran imitated Chinese white stoneware by covering their 9th–10th century buff or red earthenware with white slip. During the 12th–14th century, potters in Iran rediscovered or revived an ancient Egyptian process of making a ceramic body predominantly of silica-rich quartz rather than clay as used in China. This material, called fritware or stonepaste, produced a harder and more durable ceramic body compared to the earthenwares. Nevertheless, provincial kilns continued to create decorative, utilitarian earthenware well into later periods.