Eur. Phys. J. Plus (2018) 133: 355
https://doi.org/10.1140/epjp/i2018-12223-7

Regular Article

Characterization of the wall paintings in La Casa de los Grifos of Roman city Complutum

¹ Geosciences Institute, CSIC-UCM, C/Doctor Severo Ochoa, 7, 28040, Madrid, Spain
² Dept. of Biology, Ecology and Earth Sciences (DIBEST), University of Calabria, Rende (CS), Italy
³ UAM, Ciudad Universitaria de Cantoblanco, 28049, Madrid, Spain

^* e-mail: duyguerg@ucm.es

Received: 31 May 2018
Accepted: 3 August 2018
Published online: 10 September 2018

Abstract

By the joint use of traditional techniques and portable non-invasive instrumentations, we investigated different wall painting samples taken from the domus, La Casa de los Grifos, of Roman site, Complutum, which is located in World Heritage Site Alcalá de Henares (Madrid, Spain). The aim of the study was to characterize the wall paintings and different layers of supporting mortars. For this portable X-ray fluorescence (XRF) device and portable Raman spectrometer were used for the pigment identification. Complementary micro-destructive laboratory techniques (Polarised Optical Microscopy (POM), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM-EDS) and Fourier Transform Infrared Spectroscopy (FT-IR)) were used on the same samples to further investigate the petrography, mineralogy and pigment composition. In addition to the experiments on collected non-restored samples, spectrophotometric measurements in the laboratory and their associated colours in situ were compared, to see the colour difference. The results allowed the characterization of materials in the painted surface layer together with the mortar support, providing useful information about the painting technologies and for suitable restoration processes.