PIXE, SEM and RAMAN analysis of pictorial materials from the VIII century crypt of San Salvatore, Brescia (Italy)

The complex of Santa Giulia of Brescia (Italy) is a great and extensively studied architectural and archaeological site, of which the church of San Salvatore is an emblematic monument. This study, conducted in the crypt of the church, implements what was published from non-destructive particle induced x-ray emission (PIXE) examination of the painting materials with structural and compositional analyses by Scanning Electron Microscopy and Raman spectroscopy. These analyses produced new and decisive data for a correct identification of the pictorial palette. We also added a photographic documentation in a few bands of the electromagnetic spectrum. The review of all data and their complementarity has allowed a more sound insight into the pictorial techniques used for the crypt's decoration. This work integrates the archaeological studies conducted on the crypt and, together with them and in comparison with data from coeval monuments, confirms in the church of San Salvatore the use of products and techniques typical of the Longobard Period.