LIBS/Raman Spectroscopic Analysis of Pigments in a Roman Fresco

In this paper, results are reported on the analysis of a fragment of roman fresco, presumably dated from I century AD. The analysis of the pigments used in the fresco has been performed using the two complementary techniques of micro- LIBS and micro-Raman spectroscopy. Both the techniques allo for microscopic analysis of the samples: however, while micro-Raman spectroscopy gives information on the surface structure of the pigments and binders used, micro-LIBS gives quantitative information on the elemental composition of them, also allowing for stratigraphic analysis with lateral spatial resolution comparable to the micro-Raman technqiue. The joint use of (mu) -LIBS and (mu) -Raman spectroscopy allows for a complete characterization of the sample, and is particularly useful in cases when one of the techniques is not able to give by itself a clear information on the nature of the pigment under study.