Roman silver coins were cut with copper

A collaboration of British scientists find that the silver content of Roman coins was as low as 86%.

Researchers at the University of Warwick, the University of Liverpool and the Rutherford Appleton Laboratory have found that silver Roman coins had been cut with copper around 90BC.

The five-year project, Rome and the Coinages of the Mediterranean 200BCE-64CE, has found that the silver content of the coinage declined in two stages, so that by 87BC it was deliberately alloyed with 5-10% copper.

The denarii dropped initially to 95% fine, and then again to 90%, with some coin silver content as low as 86%.

The researchers explain that after 91 BC the Roman state was on the verge of bankruptcy due to a war in Italy causing a debt crisis. Dr Matthew Ponting from the Unviersity of Liverpool says that this suggests a severe currency crisis.

The currency debasement is greater than historians had previously understood and sheds light on a reference by the Roman statesman and lawyer Marcus Tullius Cicero to a financial crisis.

In De Officiis, Cicero says, 'the coinage was being tossed around, so that no one was able to know what he had.'