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  • 1 Facultés Universitaires N.D. De la Paix Laboratoire d'Analyses par Réactions Nucléaires (L.A.R.N.) 22 Rue Muzet B-5000 Namur (Belgium)
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Abstract  

By using strictly non destructive and non radioactive methods of elemental analysis (PIXE and PIGE), using a 3 MeV proton beam to induce prompt emission of characteristic X-rays or gamma-rays of the elements and simultaneous photon-spectroscopy with energy dispersive solid state detectors [Si(Li) and Ge(Li)] followed by a computer assisted data handling system, we have determined the relative amounts of copper, silver, cadmium and gold at the surface of more than 30 ancient gold objects. Results on only two items are discussed here. Traces or significant concentrations of cadmium have been detected at nearly all points on or in the neighbourhood of solders on many objects dating from Roman to early Byzantine times. Cadmium concentrations range between 2 to 75 parts per thousand. This range of variation and the relative concentrations of Au, Ag, Cu and Cd at the surface of the objects studied are very different from the figures obtained during analyses of modern soldering alloys. New approaches to solve the problem of Cadmium in ancient jewelry are indicated.