The chemical composition of glass beads and their morphological characteristics can reveal where they come from. Archaeologists from the University of Geneva analyzed glass beads found at rural sites in Mali and Senegal from between the 7th and 13th centuries AD. The scientists demonstrate that the glass they are made of probably came from Egypt, the Levantine coast and the Middle East. The results show that international trade linking Africa to Europe and Asia during was connected with local and regional trade.