Multi-technical study of silver denars from medieval Poland for an improved understanding of their archaeological context and provenance

Abstract

This paper discusses a methodology that involves the use of X-ray fluorescence (XRF), high-energy particle-induced X-ray emission (HE-PIXE) and high-energy particle-induced γ-ray emission (HE-PIGE) spectroscopies for the study of historic denars with the aim of describing the advantages and limitations of each technique as well as arriving at an archaeometric interpretation of the compositions. A total of 39 medieval Polish denars minted by kings Bolesław the Brave and Mieszko II Lambert were analysed for their elemental composition. While XRF is limited to the analysis of the material close to the object's surface, high-energy ion-beam analysis (HE-IBA) was used to obtain information from Cu at a relatively larger depth. The major elements detected were Ag and Cu, while the minor elements were Pb, Au, Bi and Zn. An evaluation of the results obtained with the different techniques shows that the content of Cu near the surface is different from the bulk composition of the coins. The obtained elemental composition was used to proliferate the understanding of chronological changes in the production of early medieval Polish denars.