Raman/XRF/EDX microanalysis of 2nd-century stuccoes from Domus Valeriorum in Rome

Abstract

Abstract 2nd-century stucco fragments from the roman Domus Valeriorum were analyzed by Raman spectroscopy (Raman), imaging X-ray fluorescence (XRF) and energy dispersive X-ray microanalysis (EDX) in order to identify the pigments and materials thereon. Cinnabar, malachite, hematite, goethite and Egyptian blue were detected by the synergistic use of these techniques whereas calcite, with some traces of gypsum, was detected as materials for the bas-relief figures and the pictorial background. This non-destructive characterization is the first carried out on the Domus Valeriorum finds. The multi-analytical approach highlighted the complementarity and versatility of these techniques, suitable for both laboratory and in-situ analysis, on macroscopic or microscopic fragments without preliminary manipulation.