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A careful inspection of the Arca Avoscano funerary monument carried out during preliminary investigations allowed us to discover some traces of polychromy and gilding partially covered by grey airborne particulate deposits. In order to assess the polychromy and the gilding areas a preliminary analysis for the identification of elemental chemical composition of pigment traces by using a non-invasive application of a portable X-Ray Fluorescence (XRF) spectrometer was carried out. In some areas ambiguous results were obtained and therefore a subsequent stratigraphic examination was necessary to avoid any misinterpreting about the pigment layer stratigraphy. For this reason a successive non-invasive sampling was carried out and Environmental Scanning Electron Microscopy (ESEM) observations of cross sections as well as infrared spectrophotometric measurements were made. The results obtained showed on the ground areas of the left part of the relief the presence of blue pigments azurite-based containing a protein binding medium partially transformed into calcium oxalate. The original blue was successively covered by a white over painting of white lead and barite. The gilded robe of the Announce Virgin is formed by a preparation layer containing minium in oil medium. The gilded layer was partially covered by a white over painting of the same composition as before observed on the ground. The internal side of the robe was painted by using copper resinate which was faded into brown colour due to photochemical decomposition. A second malachite-based layer was overlapping the copper resinate. As regards gilding technique the gold leaf is applied on a oleo-resin white lead layer. In the architectonic geometrical frame decorations of the funerary monument some re-gildings were observed.