Résumé
The restoration of the Santa Vittoria reliquary conserved in the Diocesan Museum of Agrigento in Sicily at the Opificio delle Pietre Dure (OPD), Florence, was an opportunity to test various
cleaning processes on its tarnished bust made of partly gilded silver plates. The mechanical/chemical protocols used at the
OPD – calcium carbonate (CaCO3) or sodium bicarbonate (NaHCO3), and, more recently, erasers – were compared to local electrolytic cleaning techniques recently developed by
the Conservation Research Unit at Haute Ecole Arc (UR-Arc CR), Neuchâtel, Switzerland. This article presents the different cleaning processes, describes the tests carried out and shows
the results which led to the selection of electrolytic cleaning. As electrolytic treatments are new to OPD, the way in which these
technologies have been implemented is discussed.