Historical Pigments and Paint Layers: Raman Spectral Library with 852 nm Excitation Laser

Year: 2024

Authors: Innocenti S., Balbas DQ., Galeotti M., Cagnini A., Porcinai S., Striova J.

Autors Affiliation: Natl Res Council Natl Inst Opt CNR INO, Largo E Fermi 6, I-50125 Florence, FI, Italy; Univ Roma La Sapienza, Dept Sci Antiqu, Piazzale Aldo Moro 5, I-00186 Rome, RM, Italy; Opificio Pietre Dure, Viale F Strozzi 1, I-50129 Florence, FI, Italy.

Abstract: Raman spectroscopy (RS), for its robust analytical capabilities under constant development, is a powerful method for the identification of various materials, in particular pigments in cultural heritage. Characterization of the artist’s palette is of fundamental importance for the correct formulation of restoration intervention as well as for preventive conservation of artworks. Here we examine the number and variability of research studies exploiting Bravo handheld Raman spectrophotometer relying on the excitation of Raman signal with temperature-shifted diode lasers emitting at 852 and 785 nm. To this end, we explore the spectral features of common historical pigments examined as powders and in the paint layer. We show that some materials may exhibit slightly different spectra as concerns especially the relative intensity of Raman lines with 852 nm laser excitation wavelength as compared to the standard 785 nm. The aim is to provide the research community with a reference spectral database that facilitates the identification of unknown pigments using the 852 nm excitation source.

Journal/Review: MINERALS

Volume: 14 (6)      Pages from: 557-1  to: 557-27

More Information: This research was funded by PNRR H2IOSC (Humanities and Cultural Heritage ItalianOpen Science Cloud) Project (IR0000029), CUP_B63C2200073005, founded by Next Generation EU.The contents reflect only the authors’ view, and the European Commission is not responsible for any use that may be made of the information it contains. The SHINE project funding (Strengthening the Italian Nodes of E-RIHS, Avviso 424/2018 dell’Azione II.1 PON R&I 2014-2020, DD n. 461 del14-03-2019, PIR01_00016, CUP B27E19000030007) is acknowledged
KeyWords: database; historical pigments; paint layers; Raman spectroscopy; 852 nm excitation laser
DOI: 10.3390/min14060557