Non-invasive Materials Analysis Using Portable X-ray Fluorescence (XRF) in the Examination of Two Mural Paintings in the Catacombs of San Giovanni, Syracuse

X-ray Fluorescence Spectroscopy was performed to characterize pigment materials in a preliminary study of two mural paintings in the Catacombs of San Giovanni. XRF was one non-invasive, analytical technique employed as part of a comprehensive examination, which also included multispectral imaging and 3D modeling. XRF analysis contributed towards a better idea of the materials present, but definitive assignments for the pigments were not possible. The murals show some signs of degradation products including a calcium sulfate surface encrustation, and a bluish-black copper based pigment, which we suspect is the degradation of azurite into tenorite.