ANCIENT EXPLOITATION AND USE OF COBALT ALUMS FROM THE WESTERN OASES OF EGYPT*

Cobalt alums from the Western Oases of Egypt were used in the second millennium bc as a colorant to produce dark blue glasses and glazes. A collection of these alums was gathered together and analysed by a series of techniques to accurately characterize them. They were then used alongside artificial analogues in experimental work aiming to determine the process that was used to convert the raw alum into a suitable pigment that might be used in a glass. Finally, the broader picture of the use of these alums is considered together with the implications for the trade in these materials across the Near East and into Europe.     

ACCESSING PAST BELIEFS AND PRACTICES: THE CASE OF LEMNIAN EARTH*

Lemnian Earth, a medicine in the shape of a stamped clay tablet (sphragis) from Lemnos, northeastern Greece, was much valued in antiquity and in the post‐medieval period as an antidote to poison and a treatment for other ailments. Although it was among the first archaeological materials to be subjected to chemical analysis (in 1807), there is still no clear understanding as to what made Lemnian Earth an effective medicine. We argue that Lemnian Earth, the artefact, was not the same as Lemnian Earth, the raw material. We suggest a composition for the artefact by scrutinizing the documentary evidence for its properties and by considering the geochemical processes that led to the formation of the raw material and the ritual relating to its extraction. The study of the latter highlights the need for archaeological materials scientists to recognize ritual as a possible manifestation of physical and chemical processes carried out within the framework of past beliefs and practices.