Visigothic Jewellery: A Technical Study of Glass Used as Gems in Belt Buckles from a Spanish Necropolis

In this work, we studied coloured and colourless glass used as gems in Visigothic buckles possibly originating from the necropolises of Torredonjimeno, Duraton or Castilltierra in Spain. Scanning electron microscopy (SEM) with energy‐dispersive analysis (EDS) and observations made with an optical microscope in reflected and transmission mode were performed in order to establish the composition, origin of the colour and decay process of these glass pieces. The chemical analysis of ancient glass can provide relevant information regarding the manufacturing approach used during a specific period. The results revealed the presence of various transition metal elements used as chromophore elements, as well as some metallic backing foils used to improve the colour of pieces of almost colourless glass.