Egyptian blue in etruscan funerary wall paintings: A multi-analytical study from the Monterozzi necropolis (Tarquinia)

The Monterozzi Necropolis in Tarquinia (Italy), a UNESCO World Heritage site, is one of the most important contexts for Etruscan wall painting, with over 100 decorated tombs dating from the 7th to the 3rd century BCE. Despite its significance, the materials and manufacturing techniques of these murals remain partially investigated. To address this, the ARANTH campaign (Archaeometric Research on Ancient Tarquinian Heritage), promoted by PACT (Archaeological Park of Cerveteri and Tarquinia), focuses on identifying and mapping Egyptian blue in five painted tombs. The campaign adopts an interdisciplinary approach integrating multi-analytical and imaging techniques, with the participation of Pegaso S.r.l. (Multispectral and Archaeometric studies on ancient Painting Project) and access to the MOLAB platform of E-RIHS.it (Italian node of the European Research Infrastructure for Heritage Science). The study employed Visible-Induced Infrared Luminescence (VIL), VIS–NIR hyperspectral analysis, point-based visible fluorescence spectroscopy, Raman spectroscopy, X-ray fluorescence (XRF), UV–VIS–NIR reflectance spectroscopy, and external reflection FT-IR spectroscopy. Additionally, the stratigraphic analysis of a micro-sample from the Tomba del Barone was thoroughly carried out. The results enabled the identification and mapping of Egyptian blue as both a primary pigment and as in combination with other pigments across green, red, blue, and whitish areas. Notably, a new application of micro-fluorescence in the near-infrared on cross-sections allowed the rapid localization of luminescent grains, which were then unequivocally identified by micro-Raman spectroscopy, providing new insights into the spatial distribution of Egyptian blue within the pictorial layers. Furthermore, in the Tomba del Barone azurite was identified in areas where traces of blue pigment were observed, representing the first documented occurrence of this pigment in Etruscan mural painting and offering novel evidence on pigment use and painting technology in Etruscan funerary contexts.