SEM/EDS Analysis of Incrustations Coming From the "Fontana delle Tartarughe" (Turtles Fountain) Located in Rome, Italy

In the present study we tested and analysed the incrustations that were covering, before the recent restoration works, the whole surface of the “Fontana delle Tartarughe”, located in Piazza Mattei in Rome. Visual observation and "in situ" colorimetric analysis showed that the incrustations, produced by both the fountain and rain water, had a green/grey colour with some grey-brown veins, due to corrosion products generated by the interaction of the fountain bronze statues with the environment. The "in situ" X-ray fluorescence (XRF) analysis revealed the presence of copper but, due to its very low content in the calcite matrix, and the different nature of the copper products in the incrustation samples, it was impossible to obtain further information on its speciation state neither by X-ray diffraction (XRD) nor by simple stoichiometric elaboration of the data coming from Scanning Electron Microscope with X-ray microanalysis (SEM/EDS). Principal Component Analysis (PCA) of data was tried to cross-check the obtained results.