Something old, something new: the late antique mosaics from the catacomb of San Gennaro (Naples)

Naples assumed an important political and economic role within the region of Campania during the late antique period. LA-ICP-MS data of 285 glass tesserae from the catacomb of San Gennaro in Naples confirm that the surge in building activities in the late fourth and early fifth century CE was accompanied by imports of new materials for the production of mosaic tesserae. Our results from Naples identify a substantial number of Jalame-like Levantine glasses for which there is no parallel within the Italian Peninsula. Only few scattered examples of this type of base glass are found among the published data from Aquileia, Ravenna and the Villa of Faragola, pointing to a link between the supply of glass and the sites' connectivity and economic strength. This seems to have changed after the fifth century. Elemental analyses, combined with SEM-EDS and micro-Raman indicate that the mosaics dating from the fourth to the eighth/ninth century CE in the catacombs of San Gennaro were overwhelmingly made from reused first- to fourth-century Roman base glasses opacified with calcium antimonate. The reuse and recycling of Roman glass and Roman tesserae is a common feature of mosaic assemblages in Italy more generally. The definition of a Roman spectrum tesserae reference group revealed this dependence on old Roman material throughout the first millennium CE.