...the sources of silver used to produce Roman coinage have largely been used up, making it difficult to determine which deposits Roman miners exploited...The Iberian Peninsula, which includes modern Spain and Portugal, is host to world-class silver deposits, especially in the southern region. These deposits contain galena, which is the main ore of lead and an important source of silver. To extract silver, the galena ore is smelted and purified, with refined silver for coin minting able to reach a purity of over 95%.To track the source of Roman silver, the team of researchers analyzed the silver and lead compositions...