Among the astonishing number of findings, inside and outside the buildings, a large amount of glass mosaic tesserae were gathered from the thermal bath environments. The archaeological excavation of the Villa dei Quintili in Rome (2nd century AD) brought to light one of the most impressive residential complexes of the Roman Empire. Three glass types and some recipes not attested before in this chronological range for the production of tesserae are documented, such as the use of a local low-chlorine natron glass for the production of black and red tesserae, the blue colouring by a source of cobalt with zinc in a natron glass tessera and the opacification with tin oxide (both in a lead-free and in a high-lead natron glass), as well as with quartz. In the church, the samples attest a technological change from Roman tradition, and a complex pattern according to building history (two phases are attested, probably in the sixth and eighth to ninth c.), and a multiplicity of supply. They were made using a Levantine 1 raw glass, generally attributed to the early Byzantine period (fifth to sixth c.). In the destruction layers of the theatre, tesserae produced following the Roman glassmaking technology (natron glass opacified by calcium and lead antimonate) were found. The aims are to add new information to the scant knowledge of the Byzantine glassmaking technology, to constrain the chronology of the mosaics and to trace the supply routes of the tes-serae. Philip) are analysed by particule-induced X-ray emission and particule-induced gamma ray emission and electron probe X-ray microanalysis to obtain the chemical composition and identify the colourants and opacifiers. Fifty-seven samples of loose tesserae from two sites in the town (the theatre and the church of St. This study focuses on the Byzantine glass tesserae from Hierapolis (Phrygia, central Turkey). Copper and cobalt were employed in both green and blue glasses to produce different shades of colour (grey, tints of green, dark and light blue). EPMA-WDS results prove the use of Sn-Pb antimonates to create yellow glass, and of cuprite to obtain the red colour. The glasses show the typical soda-lime-silica composition. The aims of the study were (1) the determination of the chemical composition and the technology of glass mosaic tesserae production (2) the individuation of colouring and opacifying agents used for the production of the glass tesserae. The coloured glass tesserae were analysed through a micro-analytical approach using an Electron Probe Micro Analyser with Wavelength-Dispersive Spectroscopy (EPMA-WDS) and Laser Ablation with Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). Aloe quarter in Vibo Valentia (Calabria, Italy).

This work reports the results of the archaeometrical investigation performed on twenty glass tesserae collected in 2018, during the restoration of the Four Seasons mosaic, which dates between the second and the third century AD, in the archaeological area of the S.

Gold tesserae