The characterization of roman wall paintings fragments. An insight into pigments and materials in Roman Sardinia (Italy)

The fragments of wall paintings from Turris Libisonis (Porto Torres) are interesting in order to characterize and compare the materials used in this colony with other case studies in different regions and provinces of the empire itself and to shed light on pigments and the use of colour in Roman Sardinia, a relatively undeveloped field of research, with a few published case of studies, besides the city of Nora. The thirty-one fragments, dating mostly between the 1st and 3rd century CE, are exhibited in the Antiquarium Turritano in the modern city of Porto Torres, built on the ancient roman city, in the northwest of Sardinia. They were analyzed through a well-established protocol that includes non-invasive and portable techniques, such as Multiband Imaging techniques (MBI), X-ray fluorescence spectroscopy (XRF), Total Reflection Fourier Transform Infrared Spectroscopy (TR -FTIR), Raman spectroscopy and Optical Microscope documentation. The analyses were carried out directly in the museum preventing any excessive handling of the pieces and the sampling, allowing the preservation of the fragments with the aim of maximum protection of these unique artefacts. The results obtained can form a first dataset of information about the wall painting in Turris Libisonis and become useful support for the archaeologists in the study of the wall painting in Roman Sardinia.