Chemical characterization of vitreous finds from cosenza cathedral (calabria - italy) by the combined use of analytical techniques

Abstract

This article presents an archaeometrical research carried out on twenty-six vitreous finds collected in the Cosenza Cathedral (Calabria, Italy). The glasses have been subdivided in two typo-chronological groups. The first group is composed of 14 vitreous samples dating to the 4th-6th century AD. The second group includes twelve samples; seven are stems of funnel-shaped hanging lamps which date between the 12th and the 13th century AD, two are bottlenecks of balsamaria and three are concave bases. The aims of this study were the determination of the chemical composition of vitreous finds and the individuation of the primary glass sources. The samples were characterized through Electron Probe Micro Analyser with Wavelength Dispersive Spectrometer (EPMA-WDS) and Laser Ablation with Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). The data confirm that all the finds of the first group are "silica-soda-lime"type glasses characterized by a high content of Na2O and a low content of K2O and MgO. On the contrary, the samples of the second group, showing higher contents of K2O and MgO, are vegetable silica-soda-lime glasses. Their composition confirms the typological attribution to the medieval period.