A Scientific Approach to Cultural Heritage Preservation: A Case Study of Vandalistic Acts on Important Roman Mosaics

As an example of the way in which a scientific study can help the restorer in the restoration of important artistic works, the authors report the case study of vandalistic acts on important Roman mosaics. On the night of September 29, 1995, some unknown vandals poured dark brown paint over several of the most beautiful and important mosaics of the Villa del Casale (Piazza Armerina, Italy). The villa, consisting of an extensive network of rooms, galleries, courtyards, and baths, contains some of the largest and most beautiful mosaics surviving from Roman times. Chemical investigations were performed in order to draw up a rapid restoration plan aimed at identifying the substances used and proposing a correct restoration procedure. A multitechnique, analytical approach was used for these investigations because of the highly complex heterogeneity of the materials studied. The results showed that toluidine red was present in the paint as pigment and that the vehicle was made up of a mixture of alkyd resins, together with styrenated compounds and unsaturated long chain-containing oils. Moreover, besides compounds like calcium carbonate, barium sulfate, and aluminum oxide, silver-containing compounds were present in the paint. All of these observations allowed the authors to propose the removal method to be adopted that achieved the restoration of the mosaics.