A numismatic study of Roman coins through X-ray fluorescence and X-ray computed μ-tomography analysis

Thirteen of a group of thirty Roman coins, found in the so-called “Grotta delle Ninfe” near Cerchiara di Calabria (Calabria, Italy) and preserved in the Brettii and Enotri Museum showcase in Cosenza (Calabria, Italy) have been under archaeometric investigation. The coins have followed a degradation process due to the sulphurous water source near the discovery site. Due to a thick layer of corrosion products, the inscriptions are entirely unreadable. This paper aims to know the constituent material and find hidden signs or inscriptions on the coins using X-ray fluorescence (XRF) and X-ray microtomography (μ-CT). Employing the X-ray μ-CT, we made some inscriptions readable, and through a numismatic study, we learned the provenance of the coins and their period of manufacture.