A Non-Destructive Multi-Analytical Approach for the Compositional and Structural Characterization of a Renaissance Crucifix

This work focuses on the characterization of a Renaissance crucifix from a private collection in Messina (Sicily), utilizing an integrated non-invasive protocol to examine its composition, structure, and internal assembly. The analytical sequence combines high-resolution digital optical microscopy with three-dimensional surface reconstruction, clinical computed tomography (CT) for internal structural imaging, and Fourier-transform infrared spectroscopy in attenuated total reflectance (FTIR-ATR) mode for material identification. This combined approach enabled a direct correlation between external surface morphology and hidden internal construction. CT diagnosis has successfully mapped the internal joinery of the sculpture, revealing distinct sections secured by internal wooden joints, while FTIR spectroscopy has enabled the chemical identification of the materials that CT could only localize based on their physical density. Beyond the specific case study, the results demonstrate the high potential of combining complementary non-invasive tools to unlock the structural secrets of multi-part or assembled historical artifacts without the need for destructive sampling.