Archaeometric studies on a Pompeian blue glass fragment from Regio I, Insula 14 for the characterization of glassmaking technology

Abstract

A Pompeian glass sample found in Reg. I, Insula 14, during the 1950’s Pompeii excavation was examined by Raman and Fourier transformed infrared spectroscopy, scanning electron microscopy, and inductively coupled plasma mass spectrometry. The analyzed specimen was selected based on its intense blue color and its well-preserved aspect. The purpose of the work was the chemical characterization of Pompeii’s glass in correlation to the actual knowledge of Roman glassmaking technology from the Mediterranean area. The results suggested that the Pompeii’s glass was a soda-lime-silica glass, but with a higher calcium content that, given the low content of lead, was used to stabilize the glass. The sample was in origin produced most likely as non-decolorized primary raw materials from eastern Mediterranean sites. Moreover, the intense blue color was related to the use mainly of cobalt, present in a weighty amount, and likely used as important coloring agents in the ancient secondary glass-making workshop.