Sources of early Islamic silver: lead isotope analysis of dirhams

Abstract

The expansion of the early Islamic state ( c . AD 700–900) was underpinned by the minting of silver coins ( dirhams ) on an enormous scale. While the wider effects of this coinage have been studied extensively, the sources of silver have attracted less attention and research has relied on literary texts pointing to mines in Arabia and Central Asia. Here, the authors use lead isotope and trace element analyses of more than 100 precisely dated silver coins to provide a geochemical perspective on Islamic silver. The results identify multiple new sources, stretching from Morocco to the Tien Shen, and indicate an Abbasid-period mining boom. These source locations have implications for contemporary geopolitics including on the Islamic-Byzantine frontier.