Palladium analysis in gold items from Punic jewellery (Cádiz, Spain)

Some years ago a group of jewels from the Museum of Cádiz (South Spain) was analysed by micro-PIXE (Particle Induced X-ray Emission) at Centro Nacional de Aceleradores (Sevilla). During this work two similar spiral earrings happened to have significant amounts of palladium in their composition, up t...

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Bibliographic Details
Authors: Ortega-Feliú, Inés, Gómez Tubio, Ana María, Scrivano, Simona, Ager Vázquez, Francisco José, Bandera Romero, María Luisa de la, Respaldiza Galisteo, Miguel Ángel
Format: article
Status:Versión aceptada para publicación
Publication Date:2020
Country:España
Institution:Universidad de Sevilla (US)
Repository:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/167862
Online Access:https://hdl.handle.net/11441/167862
https://doi.org/10.1016/j.radphyschem.2019.03.043
Access Level:Open access
Keyword:Palladium
Gold
X-ray fluorescence
Punic jewellery
Cádiz
Description
Summary:Some years ago a group of jewels from the Museum of Cádiz (South Spain) was analysed by micro-PIXE (Particle Induced X-ray Emission) at Centro Nacional de Aceleradores (Sevilla). During this work two similar spiral earrings happened to have significant amounts of palladium in their composition, up to 0.7 wt%, and some hypotheses about the provenance of this palladium-bearing gold were exposed. Many similar gold earrings from the same location and time are kept in the museum, some of them permanently exhibited in the showcases. Now, by means of a portable X-ray spectrometer device, especially designed for the analysis of gold jewels, a second campaign has been accomplished to study the rest of the jewels kept at the museum. This time the equipment was moved to the museum instead of taking the gold items to the laboratory, facilitating the analysis of the samples in the showcases and reducing the costs. A total of 94 jewels have been studied and 24 of them contained palladium up to 1.1 wt%. Copper content was below 2.5 wt% in most of the cases. X Ray Fluorescence technique was employed for this study. A filter of 20 μm of Zn was used in the detector to enhance the detection of palladium, and other potential platinum group elements, by absorbing the Au-Lα emission line. The effects of this method in the quantification was also compared in this work, finding higher uncertainties with the use of the filter, but demonstrating the convenience of its use to discriminate the Pd-Kα line from the sum peaks of the very intense gold lines.