On the origins of tin-opacified ceramic glazes: New evidence from early Islamic Egypt, the Levant, Mesopotamia, Iran, and Central Asia

It has been generally accepted that the beginnings of tin-based opacification of ceramic glazes is associated with the white glazed wares excavated in Iraq and western Iran and dated to the ninth century AD (so-called 'Samarra-type' pottery). This paper focuses on an earlier stage in the technological development of tin-opacified glazes, that is, the yellow and white glazed wares produced from the eighth century AD in Egypt and the Levant. In addition, the compositional data was extended for the subsequent spread of tin-opacified glazes into Mesopotamia in the ninth century and Northern Iran and Central Asia in the tenth century. Using SEM-EDS and SR-Micro-XRD, the chemical composition and microstructure of eighty-five samples of opaque yellow and white glazed wares from Egypt (Fustat), the Levant (Madaba, Aqaba, Al-Mina and Raqqa), Mesopotamia (Samarra, Kish, Basra and Susa), Northern Iran (Takht-i Suleiman), and Central Asia (Nishapur, Merv and Samarqand) were investigated. These data confirmed that the yellow and white glazes were opacified by lead-tin-oxide (PbSnO3) and tin oxide (SnO2) particles respectively. Replication experiments were then conducted to imitate typical compositions of the analysed opaque yellow and opaque white glazes. Overall, the results posited the beginning of tin-based opacification of glazes in the eighth century in Egypt and the Levant, and provided explanations as to how the production of opaque yellow and white glazes in the Levant and Mesopotamia might have been technologically linked.