Energy dispersive X-ray fluorescence (EDXRF) is a well-known technique for non-destructive and in situ analysis of archaeological artifacts both in terms of the qualitative and quantitative elemental composition because of its rapidity and non-destructiveness. In this study EDXRF and realistic Monte Carlo simulation using the X-ray Monte Carlo (XRMC) code package have been combined to characterize a Cu-based bowl from the Iron Age burial from Fareleira 3 (Southern Portugal). The artifact displays a multilayered structure made up of three distinct layers: a) alloy substrate; b) green oxidized corrosion patina; and c) brownish carbonate soil-derived crust. To assess the reliability of Monte Carlo simulation in reproducing the composition of the bulk metal of the objects without recurring to potentially damaging patina's and crust's removal, portable EDXRF analysis was performed on cleaned and patina/crust coated areas of the artifact. Patina has been characterized by micro X-ray Diffractometry (μXRD) and Back-Scattered Scanning Electron Microscopy + Energy Dispersive Spectroscopy (BSEM + EDS). Results indicate that the EDXRF/Monte Carlo protocol is well suited when a two-layered model is considered, whereas in areas where the patina + crust surface coating is too thick, X-rays from the alloy substrate are not able to exit the sample.

This work is part of a broader research line that aims to develop and implement a nondestructive methodology for the chemical characterization of archaeological metals based on a protocol that combines energy dispersive X-ray fluorescence spectrometry (ED-XRF) with a Monte Carlo (MC) simulation algorithm. In this paper, the ED-XRF/MC protocol has been applied to estimate the chemical composition

The hoards of metallic objects belonging to the Late European Bronze Age can be interpreted differently depending on the type, number and composition of the artefacts. PIXE analysis has been performed in nine items from the Hoard of Freixanda in Portugal comprising 4 socket axes, a palstave axe, a ring, a chisel, a dagger, and a casting debris. Besides the composition of the main matrix elements, that is Cu and Sn, the amount of trace elements of interest like, As, Pb, Ni and Ag has been determined using this ion beam technique. The high tin content alloy and the high purity of the metals from the Freixanda hoard are characteristic of the Portuguese and Spanish Late Bronze Age metallurgy, supporting the idea of a regional production.

Energy dispersive X‐ray fluorescence (EDXRF) is widely used in the study of archeological metal artifacts, heritage and art history, where the fragile nature of the objects requires the use of noninvasive techniques such as the EDXRF, which in addition, is fast and very affordable. An EDXRF analysis of copper‐based artifacts from Late Bronze Age metal hoards from Central Portugal is presented. The EDXRF measurements were carried out by using an X‐ray tube with a Mo anode and a commercial Si‐PIN detector. The data acquisition was performed by keeping small distances between the X‐ray window, the sample and the detector. Both patinated and polished areas were analyzed: the relative composition of the artifacts was inferred from the fluorescence spectra obtained. Copyright © 2012 John Wiley & Sons, Ltd.

This study is part of a wide-scale research on metal production in South-Western al-Andalus during the Islamic period, under the project "DE RE METALLICA -DEfining and REdiscovering MEtallurgy and Trade in AL-Andalus (8th-13th centuries AD): Leaping into Innovative Comprehensive Archaeometric Approaches". In particular, this paper presents the results of the elemental analysis carried out on a group of six Islamic oil lamps found at different sites in Southern Portugal, spanning from the 10th to the 13th centuries AD. Due to the exceptional historical value of these artefacts, the analyses were carried out according to a completely non-destructive approach that combines Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF) with a Monte Carlo (MC) simulation code named X-ray Monte Carlo (XRMC). This novel and ground-breaking approach has proven to be especially suitable for non-destructive analysis of artefacts with a multi-layered structure, such as archaeological metals, being able to estimate the composition of the original alloys and to characterise the structure and composition of each layer superimposed to the bulk with no need of removing samples or cleaning the artefacts' surface from corrosion compounds. The application of the EDXRF/MC analytical protocol revealed that the six oil lamps selected for this paper are covered by a structure composed of three different layers (protective layer + corrosion patina + alloy). The bulk metal is a copper-based alloy with a great variability in terms of Fe, Zn, Sn, As, and Pb, likely suggesting either the use of scrap metals as raw material or the indiscriminate addition of different kind of minerals. With regard to the objectives of this paper, EDXRF/MC protocol successfully allowed to estimate the chemical composition of the six oil lamps in a completely non-destructive way, thus representing a viable compromise between the necessity to ensure their physical integrity and the need to obtain reliable analytical data able to address historical issues.Publisher's Note The EPJ Publishers remain neutral with regard to jurisdictional claims in published maps and institutional affiliations.