Electron Spin Resonance Characterization and Provenance of Marbles: The Case of the “Cipollino Verde”

The possibility of using Electron Spin Resonance Spectroscopy (ESR) for identifying the quarries of provenance of classical marble artifacts has been reexamined and applied to the sample case of the so-called "Cipollino Verde" marble. The method gives qualitative and quantitative information on Mn2+ and other paramagnetic impurities present in marble and the assignment is made on a statistical basis, using a properly defined database. Like other, well established, techniques, ESR seldom yields an unequivocal answer to the provenance problem. However, it provides valuable information and, coupled with other methods, reduces the existing uncertainties often leading to the final assignment.