Synchrotron Radiation-Induced X-Ray Fluorescence (SRXRF) Analyses Of The Bernstorf Gold

摘要

The gold finds from Bernstorf, in the Freising district of Bavaria, were discovered in 1998, in the area of a Bronze Age settlement. First analyses with X-ray fluorescence (XRF) revealed gold of an unusually high purity grade, which was explained by the use of cementation techniques. A newer analysis with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) indicated an even higher purity. The analytical results were the starting point of an ongoing discussion. In this study, we re-analysed 11 gold samples with synchrotron radiation-induced X-ray fluorescence at the BAMline at BESSY. In a thorough analysis, different excitation and detection conditions were applied to confirm or disprove the previous results. It was shown that the purity of the gold from the specimen is higher than 99.9%. The main impurities are silver in a range between 20 and 200gg(-1) and copper between 1 and 10gg(-1). The results are in very good agreement with the LA-ICP-MS measurements and provide basic information for discussions about provenance, processing techniques or considerations of authenticity.