Non-invasive quantitative micro-PIXE-RBS/EBS/EBS imaging reveals the lost polychromy and gilding of the Neo-Assyrian ivories from the Louvre collection

Marie Albéric; Katharina Müller; Laurent Pichon; Quentin Lemasson; Brice Moignard; Claire Pacheco; Elisabeth Fontan; Ina Reiche

doi:10.1016/j.talanta.2015.01.029

Non-invasive quantitative micro-PIXE-RBS/EBS/EBS imaging reveals the lost polychromy and gilding of the Neo-Assyrian ivories from the Louvre collection

Talanta. 2015 May:137:100-8. doi: 10.1016/j.talanta.2015.01.029. Epub 2015 Feb 7.

Authors

Marie Albéric¹, Katharina Müller¹, Laurent Pichon², Quentin Lemasson², Brice Moignard², Claire Pacheco², Elisabeth Fontan³, Ina Reiche⁴

Affiliations

¹ Sorbonne Universités UPMC University Paris VI, UMR 8220, Paris, France; Laboratoire d׳Archéologie Moléculaire et Structurale (LAMS), UMR 8220 CNRS UPMC, Paris, France.
² Centre de Recherche et de Restauration des Musées de France (C2RMF), Paris, France.
³ Département des Antiquités Orientales, Musée du Louvre, Paris, France.
⁴ Sorbonne Universités UPMC University Paris VI, UMR 8220, Paris, France; Laboratoire d׳Archéologie Moléculaire et Structurale (LAMS), UMR 8220 CNRS UPMC, Paris, France; Rathgen-Forschungslabor, Staatliche Museen zu Berlin, Stiftung Preußischer Kulturbesitz, Berlin, Germany. Electronic address: ina.reiche@upmc.fr.

PMID: 25770612
DOI: 10.1016/j.talanta.2015.01.029

Abstract

Antique objects are known to have been brightly colored. However, the appearance of these objects has changed over time and paint traces are rarely preserved. The surface of ivory objects (8th century B.C., Syria) from the Louvre museum collection (Paris) have been non-invasively studied by simultaneous particle-induced X-ray emission (PIXE) and Rutherford and elastic backscattering spectrometry (RBS/EBS) micro-imaging at the AGLAE facility (C2RMF, Paris). Qualitative 2D chemical images of elements ranging from Na to Pb on the surface of the ancient ivory carvings provide evidence of lost polychromy and gilding. Quantitative PIXE data of specific areas allow discrimination between traces of sediments and former polychromy. Different shades of blue can be differentiated from particular Pb/Cu ratios. The characterization of gilding based on RBS data demonstrates the exceptional technological skills of the Phoenician craftsmen supposed to have carved the Arslan Tash ivories. More precise reconstructions of the original polychromy compared to previous studies and a criterion for the authentication of ancient gilded ivory object are proposed.

Keywords: Au NPs; Elemental imaging; Ivory; Micro-PIXE–RBS/EBS; Paints.