Nano-CT evaluation of totally corroded coins: A demonstration study to determine if detail might still be discernible despite the lack of internal, non-corroded, metal

Abstract

Five unidentifiable, completely corroded ancient coins (three of which were large fragments), proven to lack any residual internal metal, were scanned by nano-computed tomography (CT) to see if discernible detail might still be present. One fragment could be identified as an early fourth-century Urbs Roma commemorative AE 3/4. Another fragment was a coin of either Valerian or of the joint rule of Valerian and Gallienus, which could be dated to the period 254–56 ce. The other three lacked discernible detail. This proof-of-concept study shows that nano-CT scanning has the potential to allow non-invasive identification of at least some totally corroded coins.