Archaeometric studies on early medieval silver jewellery from Central and Eastern Europe

摘要

Scanning electron microscopy with X-ray microanalyses (SEM-EDX) was used for a technological study of silver jewellery from three hoards found in Poland. The assemblage consists of 26 artefacts from the period of formation of the first Polish state (9001039 AD) and can be divided into three groups: West Slavic, post-Moravian and Scandinavian. Research results provide information concerning techniques used for granulation ornament and the provenance of raw silver. Elemental composition changes are manifested mainly by different Cu contents. A higher Cu content was found in solder. The higher Cu content in relation to the morphology of the joining region with visibly spilled granulation demonstrates that the West Slavic beads were produced with the use of metallic soldering. On the other hand, other studied jewelleries are characterised by Cu, Sn, Sb and Zn enrichments in oxidised soldering regions, which implies that they were manufactured with the use of non-metallic soldering. In addition, studies on the provenance of the raw material were made based on the analysis of lead isotopic ratios. For this purpose, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used, and the obtained lead isotopic ratios were processed using linear discriminant analysis (LDA). The isotope study demonstrates that all examined artefacts were made using re-melted metal from multiple sources. The most probable sources of silver were ores from Uzbekistan, Afghanistan and Freiberg (Germany).