The classification and characterisation of archaeological glass using multi-elemental analysis

Abstract

The main aim of this thesis was to use non-destructive multi-elemental analysis to determine the major and trace elements contained in archaeological glass. There has been very little work done on elemental analysis of glass in Ireland, not least because destructive techniques are usually necessary in order to obtain a quantitative result which is representative of the entire glass object. For the purpose of this study, X-ray fluorescence (XRF) was chosen as the analytical method as it is capable of carrying out completely non-destructive multi-elemental analysis, something which is highly desirable for archaeological material. A total of 328 beads, artefacts and fragments were analysed by XRF. The objects came from a range of sites from various locations across Ireland and included glass from the Iron Age through to modern times. Using elemental analysis, it was possible to identify the raw materials, including the type of modifiers that were used as well as the colourants and opacifiers used. It was also possible to examine levels of corrosion that the surface layers had undergone, based on the amount of elements such as aluminium that they contained. The results from the analysis highlighted some interesting trends such as increased levels of aluminium over time in glass due to corrosion. Further analysis of larger groups of samples would make it easier to identify trends and changes in glass objects and could potentially highlight further indicators of chronology or geographical origin based on elemental composition.