Abstract/Summary

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.