Refining gold with glass - an early Islamic technology at Tadmekka, Mali

We describe two crucible fragments from an early Islamic context at the West African site of Tadmekka, in the Republic of Mali. They are made from a very sandy fabric and contain numerous gold particles and mineral grains in a matrix of lightly-coloured glass-based crucible slag. We interpret these as remains of a process separating freshly-panned gold concentrate from residual mineral inclusions, by melting the concentrate together with crushed glass beads. The process has similarities in modern artisanal practice, and shows the versatility of craftspeople in this major urban trading centre famous for its gold wealth.