Fast mapping of gold jewellery from ancient Egypt with PIXE: Searching for hard-solders and PGE inclusions Quentin Lemasson a,b,n , Brice Moignard a,b , Claire Pacheco a,b , Laurent Pichon a,b , Maria Filomena Guerra c a C2RMF, Palais du Louvre-Porte des Lions, 14 quai François Mitterrand, 75001 Paris, France b Fédération de recherche NewAGLAE, FR3506 CNRS/Ministère de la Culture et de la Communication/Chimie ParisTech, Palais du Louvre, 75001 Paris, France c ArchAm-UMR 8096 CNRS-University Paris 1 Panthéon -Sorbonne, MAE, 21 allée de l’Université, 92023 Nanterre, France article info Article history: Received 27 January 2015 Received in revised form 16 April 2015 Accepted 21 April 2015 Available online 5 May 2015 Keywords: PIXE Fast mapping Egypt Gold PGEs Brazing abstract A new PIXE setup at the external beamline of the AGLAE accelerator is assessed for fast mapping the joining regions and the PGE inclusions of nine Egyptian gold items from the Louvre museum collection, dated to the end of the 2nd Intermediate Period and to the New Kingdom. The setup is composed of a cluster of SDD detectors divided in two “super detectors” dedicated to analyse the matrix and the trace elements. It provides the possibility to realise large and/or fast maps on artefacts by scanning the beam over the sample surface. Different softwares have been developed or updated to visualise, process, and quantify the data. By using this setup, we could determine the elemental distribution of major elements Au, Ag and Cu on the different joining regions, estimate the composition of the brazes, and show that they were pro- duced by adding Cu to the base gold alloy. By fast mapping the PGE inclusions we could reveal a large variety of compositions within a single object. In addition to the expected Ir–Os–Ru system inclusions, we could also show for several inclusions the presence of another element, Pt. For a region where PGE inclusions overlap the joining area we could show that fast mapping allows to determine the compo- sitions of the inclusion, the brazing alloy, and the base-alloy. & 2015 Elsevier B.V. All rights reserved. 1. Gold work in ancient Egypt The few publications on the analytical study of goldwork attributed to the 2nd Intermediate Period (c. 1800–1550 B.C.) and to the New Kingdom (c. 1550–1070 B.C.) in Egypt show the use of polychrome effects within the same objects by using gold alloys with different colours [1–4] and sometimes native aurian silver [5]. A variety of gold colours could be obtained by adding Ag and Cu contents to gold from various sources. Before the introduction of parting, in the first millennium B.C. [6,7], gold objects were made with native gold from different sources, and so containing different concentrations of Ag, to which Cu could be added to enhance the colour and the properties of the alloys. Recent publications showed that gold jewellery is made with a variety of gold colours within a same tomb during the New Kingdom [2] and from high carat gold alloys to high silver electrum, even for items belonging to a single individual during the 2nd Intermediate Period [4,8]. The majority of the objects were constructed by joining dif- ferent parts. Hard-soldering or brazing seems to be widely used in the Egyptian workshops since at least the Middle Kingdom [9], and may attain a very high quality for some particular jewellery items belonging to important personages [10,11]. The brazes or brazing alloys are in this case gold alloys whose melting point is lower than the parts to be joined. In order to lower the melting tem- perature of a gold alloy, the concentration of Ag and/or Cu must be intentionally increased (by changing the native base alloy or by adding the metals). Egyptian goldworkers should have had an empirical knowledge on the melting ranges of the binary and ternary alloys of gold, copper, and silver and well practise brazing as represented on a wall painting dating from about 1475 B.C. in the tomb of the Vizier Rekh-mi-re at Thebes [12]. Gold brazes can be produced with the same technique as polychrome gold alloys, which means by addition of Cu to native gold containing different Ag contents. It is however difficult to estimate the original composition of the brazes in small objects. When running at high temperature the filler between the parts to be joined, a region where the alloys mix up tends to be formed. By Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/talanta Talanta http://dx.doi.org/10.1016/j.talanta.2015.04.064 0039-9140/& 2015 Elsevier B.V. All rights reserved. n Corresponding author at: C2RMF, Palais du Louvre-Porte des Lions, 14 quai François Mitterrand, 75001 Paris, France. Tel.: þ33 1 40 20 24 82. E-mail address: quentin.lemasson@culture.gouv.fr (Q. Lemasson). Talanta 143 (2015) 279–286