Dr Moujan Matin

© 2018, The Author(s). Tin-based opacification by tin oxide and lead-tin-oxide particles was used in glass production since the first millennium BC and in ceramic glazes since the eighth century AD. Opacification process is often characterised by significant amounts of tin oxide and lead oxide dispersed into glassy matrices or by identification of the opacifying particles by means of microstructural or (micro-)XRD analyses. The processes of opacification and manufacture are usually more difficult to establish from compositional and microstructural analyses because they leave little diagnostic traces. This review aims to integrate compositional data on archaeological glass and glazes and in particular the Pb/Sn values, with descriptions of the opacification processes in historical treatises, observations at traditional workshops, and the results of previous replication experiments to shed further light on technological issues underlying these methods of opacification and highlight new research perspectives.

© 2016 Elsevier Ltd The Nabataeans, who founded the city of Petra (southern Jordan) in the late first millennium BCE, are noted for the production of a distinctive very fine pottery with painted decoration and a wall thickness sometimes as little as 1.5 mm; this pottery appears largely locally made and not widely circulated. Using a combination of OM, SEM with attached EDS, surface XRF, and XRD, it is shown that the Nabataean fine pottery bodies were produced using semi-calcareous clays which were fired to temperatures of about 950 °C. In contrast, published data indicate that contemporary and in many ways apparently functionally equivalent Roman terra sigillata, which was traded throughout the Roman Empire, was produced using fully-calcareous clays which were fired to temperatures in the range 1000–1100 °C. Furthermore, the high gloss slip applied to Roman terra sigillata is fully vitrified whereas the red-painted decoration applied to the Nabataean pottery is unvitrified. The more robust Roman terra sigillata is therefore better suited as tableware for serving and consuming food than would be the case for Nabataean fine pottery, and would be a more successful export material.