Non‐invasive analyses of an etruscan fibula from Vulci (Italy). The benefits of a combination of Micro‐Raman spectroscopy, 3D reconstruction through X‐Ray microscopy and ED‐XRF with Monte Carlo simulation

This work investigates the composition of the patina and state of preservation of an Etruscan bronze fibula from Tomb 129 of Vulci Archaeological Park (VT, Italy), dating back between the late eighth and early seventh centuries BC. Non-destructive analytical techniques, such as micro-Raman spectroscopy and energy-dispersive X-ray fluorescence (ED-XRF) combined with Monte Carlo simulations, were used to analyze the patina's mineralogy and the alloy's chemical composition. Monte Carlo simulation was applied to model the layered structure of the fibula accurately and distinguish between the alloy and the patina, allowing the elemental composition of the fibula to be known and excluding selective depletion phenomena. Innovative 3D reconstruction through X-ray microscopy (XRM) allowed the characterization of the internal structure of the artifact and its state of preservation. Micro-Raman results on the patina identified the occurrence of brochantite and sampleite due to interactions with the burial environment and the decomposition of organic matter. The fibula was a binary bronze alloy (Cu-Sn) with a low tin content and minimal lead concentration. XRM analysis detected fragility points and a small blind hole inside the fibula, probably related to the manufacturing processes. These findings provide insight into the artifact's conservation status and contribute to a better understanding of ancient Etruscan metalworking techniques. By integrating advanced analytical methods and non-invasive imaging, this study highlights the potential of combining scientific techniques to preserve cultural heritage and deepen our knowledge of metallurgical practices in ancient civilizations.