Surface Studies of Ancient Gold Coins and Modern Copies by X-ray Fluorescence, Scanning Electron Microscopy and Scanning Auger Spectroscopy

Abstract

Several gold coins and modern copies were examined by three surface analysis techniques and the results were evaluated for possible use in authenticity testing of the coins. The coins supposedly ranged in age from 241 B.C. to 1894 A.D. The scanning electron microscope with an energy-dispersive x-ray analyzer was used to analyze for elemental composition, surface irregularities, contamination introduced during production, and accumulated debris. Conventional x-ray fluorescence provided elemental composition more representative of the bulk of the coins. Auger microprobe data provided corroborative qualitative analysis and information on the presence of low atomic number species. The significance of these results for authentication of ancient artifacts and art objects is discussed.