Complex archaeometallurgical investigation of silver coins from the XVIth-XVIIIth century.

When dealing with cultural heritage artifacts, the use of non-invasive and non-destructive analyses techniques is a must . Determination of the surface corrosion layers and coin composition is important both for identifying compounds that form different alloys (which can be considered support material for important objects, such as numismatic artifacts), and also for their conservation. The selection of analytical techniques is of great importance, as it is a strict condition that the structure of the artifacts should not be affected. The paper presents the archaeometallurgical study of seven silver coins, using several nuclear techniques (X-ray fluorescence – XRF, X-ray diffraction – XRD, Particle induced X-ray emission – PIXE) and optical microscopy. The study was performed using bulk methods and micro-area measurements in order to establish their composition, as well as the presence of corrosion products. This could, in turn, provide information in support of the categorization in genuine/possible forgery. From the analyzed set of samples, six can be surely categorized as genuine, while one raises some questions. A decisive conclusion cannot be drawn for one of the analyzed samples, but the scientific evidences suggest either a misstruck or a forgery approximately contemporary with the original issue of these coins. [ABSTRACT FROM AUTHOR]