The “ID card” of ancient materials: spectral signature, colour and thermal analysis. A tool for the monitoring and conservation of the archaeological heritage

This work introduces a methodology for characterising and representing the properties of ancient materials and structures. The results achieved are here presented for the artefacts of the archaeological site of Ancient Ostia, near Rome, which is the first case study on which the implementation of our study on the properties of ancient materials begun. The measurement techniques are non destructive techniques for in "situ" measurements, and are based on a portable spectroradiometer and a portable infrared camera. Collected data are then processed to produce the appropriate tabs for describing the optical-visual properties of materials investigated. The final aim of this work is to produce an atlas of the properties of ancient materials, whose aim is to fill a gap of knowledge, but also to create a system for the detection and control of any kind of degradation that such materials may have in time owing to natural and/or incidental causes, and for assessing the quality and durability of the interventions of conservation in archaeological sites as well. The tabs describing the properties of materials could also be considered an useful tool for an approach to the design of lighting systems, design that should be "conscious" of the reality of the archaeological sites, on one side, and of the needs for security and safety, on the other side.