This is an iconic, large size ceramic dish, with iridescent turquoise glaze with a black cross as decoration, controlled glaze around the exterior, unglazed base with a short cylindrical foot. By the 12th century, an almost revolutionary step had been taken in the pottery production of the Near East. The new body material, known as fritware was introduced in the region, either direct from Egypt or Syria. The beginning of the production of these wares borrowed elements from Chinese porcelain. Eventually, Iranian potters began to exploit coloured glazes and developed a wide range of shapes and motifs that owed nothing to China, Kashan was the main centre, producing wares of the highest quality, although evidence does point to the fact that wares of this period were also produced in different regions. Kashan was located near sources of raw materials needed to create their distinctive light-coloured stone pastes. The characteristic turquoise glaze is obtained using copper oxide as a colourant in an alkaline glaze.