1. Department of Archaeology, Conservation and History, University of Oslo, Blindernveien 11, 0371 Oslo, Norway
2. Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Viale delle Scienze Ed. 17, 90128 Palermo, Italy
3. European Synchrotron Radiation Facility, BP-220, 38043 Cedex 9 Grenoble, France
4. Sorbonne Université, CNRS, Laboratoire d’Archéologie Moléculaire et Structurale, LAMS, 4 Place Jussieu, 75005 Paris, France
5. Abteilung Kunsttechnologie, Schweizerisches Institut für Kunstwissenschaft (SIK-ISEA), Zollikerstrasse 32, 8032 Zurich, Switzerland