The Application of Multi-band Imaging Integrated with Non-Invasive Spot Analyses for the Examination of Archaeological Stone Artefacts

multi-band imaging techniques have become part of the range of analytical methodologies available in archaeological contexts, in particular ultraviolet- induced luminescence (UVL) and visible-induced luminescence (VIL). Photographic campaigns, implemented and integrated with a non-invasive or micro-invasive survey, represent a strategic tool for gaining thorough knowledge of an archaeological artefact. Specific attention is given to the study of the original polychromy on statues, in most cases reduced to tiny traces. Excavation, bad warehousing and, in some cases, excessive cleaning due to a misinterpretation of classical sculpture as totally white have led to an almost entire loss of the original polychromy. The analytical protocol here proposed, based on the combination of imaging and spot techniques, could help reveal residual traces of patterns, characteristic pigments such as red lakes and Egyptian blue and help reconstruct past restoration interventions, as demonstrated with some examples of investigations conducted in different contexts from museums to archaeological sites.