Gathering Gemology and Glassmaking

A set of more than 1000 specimens of glass gems enriches the collection of the National Archaeological Museum of Aquileia (Italy), in many different colours and transparencies. Glass classification generally follows elemental composition as for major (silica), minor (soda, ashes or potash) and trace components (B, F, Ti, Fe, but also Sb and Sn elements). Therefore, deriving the composition could return useful criteria for dating, provenance, manufacturing and trading issues. In agreement with the Museum, 40 significant glass gems were selected by colours, style, and gemmological criteria. Aim of the study will be the determination of different colouring and opacifying agents as well as the glassy or crystalline phases. In details, we want to disclose in a non-destructive way: (i) elemental composition (by NRCA), and (ii) phase composition (by ToF-ND) of the opacifying agents.