MA‐XRF analysis of ancient silver coins minted in southern Italy

At the Museo Campano (Capua, Italy), eight double‐relief silver coins belonging to southern Italian poleis and dated between the end of the 5th century and the beginning of the 3rd century BC were analysed. These coins are of great interest to historians and archaeologists because they provide extensive evidence on the monetary history and circulation of coins since the earliest times in the Campania region. Non‐invasive in situ analyses were performed using point XRF and MA‐XRF measurements and digital microscope photos. These coins were of high fineness. Data analysis methods using ROI imaging, deconvoluted maps, NMF (nonnegative matrix factorization), and k‐means were applied on the elemental maps to study the critical surface areas and to compare the effectiveness of different methods not commonly used for coins. These results combined with numismatic studies provided information on the historical context, the alloy used, and cases such as subaerati and restored coins. Important data were obtained on the currencies of the period under review, which will be useful to integrate with the analysis of further samples.