Simona Scrivano

This work arises in response to the need to understand the production techniques of pre‐roman gold jewels, starting from the systematic characterization of the different methods of metal joining used in antiquity to produce these objects. To meet this requirement, different procedures used in antiquity were reproduced by means of experimental archaeology. These models correspond to three metal‐joining methods reported by ancient recipes: solid‐state diffusion with copper salt, brazing and autogenous welding. These techniques were studied by different analytical methods in order to characterize them at both compositional and microstructural level (SEM‐EDS, metallography, μ‐XRF and μ‐PIXE). The results obtained show that the solid‐state diffusion bonding with copper salt presents a crystal hexagonal structure without phase changes in the joining point, where only a variation in the grain size is observed. At the compositional level, this soldering method is characterized by a local increase in copper concentration and a small decrease in gold content. In contrast, brazing shows a dendritic‐porous structure due to the superposition of the soldering alloy and the crystal structure of the original foils. Besides, the compositional analysis revealed an increment of silver and copper concentrations and a simultaneous reduction of gold concentration. Finally, in the autogenous welding, no changes at the microstructural and compositional levels were observed. The results obtained have also demonstrated the usefulness of a portable μ‐XRF system for the in‐situ characterization of ancient jewels. Copyright © 2017 John Wiley & Sons, Ltd.

In science applied to cultural heritage, the study of the manufacturing procedures of ancient metal artifacts is of particular relevance. In fact, metal manufacturing is correlated with the development of civilization. The aim of this work is to reconstruct, by means of experimental archeology, the ancient soldering and welding processes, in order to identify them in archeological samples using a portable micro X‐ray fluorescence (micro‐XRF) system. This portable and nondestructive technique provides a useful method for characterizing the manufacturing of ancient gold jewelry. Various gold alloys were produced with different Ag and Cu content to simulate real cases. Besides, on the basis of archeometallurgy techniques, replicas of decorations were fabricated following the ancient recipes such as those described in Naturalis Historia and Leiden Papyrus X. The content of Au, Ag, and Cu within the soldering or welding areas was quantified with the micro‐XRF technique. The methodology described in this work was applied to the particular case of alloys with high gold concentrations, such as Tartessic jewelry (700–500 BC), to identify the different welding and soldering techniques. Copyright © 2013 John Wiley & Sons, Ltd.