Application of energy dispersive X-ray fluorescence spectrometry to polychrome terracotta sculptures from the Alcobaça Monastery, Portugal

Abstract

Portable energy dispersive X-ray fluorescence spectrometry (EDXRF) was used in the Alcobaça Monastery, in order to study the chromatic coatings applied to terracotta statues that belong to two seventeenth-century monumental groupings. The main goal of this scientific approach consisted in determining the elemental composition of the constitutive layers and in trying to reconstitute the existing polychromy, taking into account the technical aspects observed at naked eye. The measurements carried out by EDXRF allowed a first material characterization of these artworks. By comparing the results obtained in each statue, it was possible to attest the application of a seventeenth-century coating to each one and at least a subsequent intervention in the form of a refurbishment or a new polychromy. According to the materials employed in their production, it appears that the refurbishment is likely dated from the 19th century while the new polychromy is still dated from the 18th century.