Research on chemical soldering in early medieval jewellery: The case of lunula-type Viking age ornaments

The aim of this paper is to discuss technological details of medieval jewellery on the basis of studies on five lunulas (the Obra Nowa hoard, Poland). The types of soldering which were applied in order to attach granules and wire to the artefact surface were studied with the use of optical microscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy, micro-Raman spectroscopy and X-ray diffraction. Results confirmed the use of chemical soldering that was based on Cu compounds with resin glue addition. The use of such addition can be assumed due to the fact that C was detected in the solder. The presence of Pb together with Ca, P, Al and Si in the soldering region is related to the use of litharge as a solder mixture component.