Prompted by their attempts to imitate the whiteness of Chinese ceramics, Abbasid potters succeeded in perfecting the first pieces of faience in the history of pottery in the late 8th and early 9th centuries. From a technical standpoint, the term faience is a clayey-paste ceramic covered with a lead-based glaze rendered opaque by tin oxide. Described as “ornaments of ink and snow”, it is in faience wares that the blue of cobalt mined in Kashan in Iran, which remained a monopoly of the Arab-Islamic world until the 14th century, made its first appearance in pottery decoration.