Investigation on four centuripe vases (late 3rd-2nd cent. B.C.) by portable X-ray fluorescence and total reflectance-FTIR

Abstract Four Centuripe vases dated back to the late 3rd-2nd centuries B.C. were analysed using imaging under visible and ultra-violet illumination as well as complementary non-invasive and non-destructive portable X-Ray Fluorescence (XRF) and Total Reflectance – Fourier Transform InfraRed (TR-FTIR) spectroscopies. The vases are of great importance since they represent a rare expression of the Hellenistic vase painting. Four specimens, a “pyxis”, a “lebes gamikos” and two “lekanides” decorated with figures of different type, are exhibited in the Antonino Salinas Archaeological Museum in Palermo-Italy. The investigation was aimed to identify the used pigments and the painting technique, to recognize the retouched areas and, eventually, to acknowledge the authenticity of these vases. Imaging techniques allowed us to have a general view of the vases, highlighting areas of probable interventions. XRF and TR-FTIR investigation was performed on selected parts of different coloured representative areas and of later restorations. The obtained results allowed acquiring information about the technology of vase production as well as on the painting technique. One of the most exciting results concerns the identification of two calcium sulphate phases: gypsum and bassanite, whose presence could constitute a criterion to discriminate original areas from later restorations or falsifications.