LIF/Raman/XRF non-invasive microanalysis of frescoes from St. Alexander catacombs in Rome

S Almaviva; R Fantoni; F Colao; A Puiu; F Bisconti; V Fiocchi Nicolai; M Romani; S Cascioli; S Bellagamba

doi:10.1016/j.saa.2018.04.062

LIF/Raman/XRF non-invasive microanalysis of frescoes from St. Alexander catacombs in Rome

Spectrochim Acta A Mol Biomol Spectrosc. 2018 Aug 5:201:207-215. doi: 10.1016/j.saa.2018.04.062. Epub 2018 May 1.

Authors

S Almaviva¹, R Fantoni², F Colao², A Puiu², F Bisconti³, V Fiocchi Nicolai³, M Romani⁴, S Cascioli⁵, S Bellagamba⁵

Affiliations

¹ ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, via Enrico Fermi, 45, 00044 Frascati, Rome, Italy. Electronic address: salvatore.almaviva@enea.it.
² ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, via Enrico Fermi, 45, 00044 Frascati, Rome, Italy.
³ Pontificia Commissione di Archeologia Sacra, Via Napoleone III, 1, Rome, Italy.
⁴ INFN-Department of Industrial Engineering, University of Rome "Tor Vergata", via del Politecnico 1, 00133 Rome, Italy.
⁵ Restauro e Conservazione di Opere d'Arte, Fiumicino, Rome, Italy.

PMID: 29753965
DOI: 10.1016/j.saa.2018.04.062

Abstract

Laser-induced fluorescence (LIF), Raman spectroscopy and X-ray (XRF) fluorescence were used to study two frescoes at the S. Alexander catacombs complex, in Rome. LIF analysis has shown the presence of a transparent protective material probably deposited in previous restoration treatments and allowed to clearly distinguish the areas undergoing the current restoration process from the ones which still have to be treated. Raman and XRF analysis allowed to non-destructively characterizing most of the pictorial materials used for the artworks, including calcite (CaCO₃), red ochre (Fe₂O₃), minium (Pb₃O₄), yellow ochre (α-FeOOH) and others. Therefore, thanks to the complementarity of the above-mentioned techniques, it was possible to obtain a detailed characterization of the studied frescoes. Finally, the whole ensemble of results constituted a valid tool to effectively plan the restoration of the frescoes.