Archaeometric analysis of patinas of the outdoor copper statue Sant'Oronzo (Lecce, Italy) preparatory to the restoration

The Sant'Oronzo statue (Lecce, Southern Italy) consists of an internal wooden structure, completely covered with copper sheets, lying on a concrete base about 1.5 m high, which is placed on the top of a Roman column about 29 m high. Lecce may be classified as urban site since it is mainly influenced by vehicular traffic and it is not affected by intense industrial emissions. In the time schedule of the restoration, first of all, non-destructive analyses were planned. In particular, a portable energy dispersive X-ray fluorescence (ED-XRF) was used in order to map the composition of the patinas and to evaluate their degradation. Subsequently, a micro-sampling was performed both of the statue and the column. The collected samples were analysed by using Raman spectroscopy and X-Ray Diffraction in order to evaluate chemical composition. This paper summarizes the archaeometric results and the diagnostic information obtained before of the re- storation, which are significant for the restorers’ subsequent work.