Abstract

Lead metallurgy has been closely associated with silver production for much of its history. It is generally accepted that galena, a lead sulfide, was the most common silver source in the early Middle Ages. Since galena can be associated with silver in the range of 0.1–0.5%, and rarely more, this indicates that tons of lead had to be laboriously processed in order to extract kilograms of silver. This study has found evidence that extremely rich silver ores must have played a key role in one of the major silver-using polities in the 8th and 9th centuries AD, despite the fact that all existing physical evidence from mines, slag, and the metal itself points to this being true: the early Caliphate of Islam.Metallic analysis of 26 coins revealed that Umayyad and Abbasid dirhams, renowned for their exceptionally pure silver, frequently contain matte inclusions (silver-copper sulfides). Silver cannot have been produced solely from lead ore or through the use of lead because the matte that was preserved in the coins could not withstand the highly oxidizing refining process required to separate lead from silver. For the understanding of early medieval extractive metallurgy, a new paradigm is required. The early Islamic silver supply greatly benefited from the processing of "dry" silver ore, which contained nearly pure silver minerals. The consequences of this study have major innovative and monetary ramifications and topple well established sees on the historical backdrop of silver metallurgy. Additionally, they have significant effects on the interpretation of elemental and lead isotope data and provenance studies.