A comparative analysis of old and recent Ag coins by XRF methodology

The investigation of silver coins dated since the first century B.C. up to recent times, coming from different countries in the world, has successfully generated a growing interest among numismatic researchers. The classification of these coins into originals, copies and imitations - according to their provenance and to their Ag content - has been performed by using the X-ray fluorescence (XRF) analysis. The archaeological challenge is to explain the large diversification of these coins, to determine the differences in composition, weight and physical aspects. A non-destructive physical method was employed to study the properties of silver coins (as in this case) allowing a detailed characterization of the analyzed samples. The XRF analysis was applied to the bulk, through an X-ray tube, and to the surface patina, through an electron beam.