Nel blu, dipinto di blu, five centuries of Blue Roman Glass from the Paletine Hill: a multi-analytical approach to provenance and production technology

Abstract

Based on a multi-analytical approach, this research aimed to characterize and compare the glass-making processes and provenance of the Roman blu glass collection, dated from the 1st century to Late Antiquity, found in the Helagabalus baths in the North East Palatine archaeological site. The samples were analysed by Optical Microscopy and SEM-EDS to identify homogeneity, glass morphological features like bubbles, inclusions and corrosion. EMPA was applied to determine the elemental composition of major and minor elements, whereas LA-ICP-MS allowed us to define trace elements. Major and minor elements, analysis, performed by EMPA, gave particular information regarding the ingredients (network former, flux, colurants and decoulourants) used in the glass batch. SEM-EDS and LA-ICP-MS in combination with EMPA allowed usto group the collection for provenance and technology information. Comparison of the data with the literature allowed to identify the raw materials provenance. This study highlighted changes in glass-making technology and provenance from the 1st to 5th of the Roman blue glass, collection. The particular study of this collection can give further information about the glass making techniques of that time.