Microanalytical study of ancient gold jewelry: Mediterranean impact on the early iron age technology in Southwestern Iberia

The gold technology in Iberia underwent an important development during the Early Iron Age (EIA) following the arrival of new technological skills from the Mediterranean region, including the use of filigree, granulation, and brazing. This work presents the microanalytical study of EIA gold jewels (22 spherical beads and four tongue pendants) recovered from three graves in southern Portugal. The set of jewelry, showing an extraordinary stylistic resemblance, was characterized by optical microscopy, micro energy-dispersive X-ray spectrometry and scanning electron microscopy with X-ray microanalysis to establish the alloy composition and production techniques. The pieces show a close technological relation, making use of artificial gold alloys with different amounts of silver (c. 40 and 25%). The decorative styles include different types of filigree (solid wires and hollow wires), while the joining techniques comprise brazing with Au-Ag-Cu solders and, probably, sintering. In spite of those technological and stylistic features, clearly pointing to a Mediterranean influence, the absence of granulation suggests an indigenous workshop where exogenous technologies/decorations were not yet fully integrated in the manufacture of such luxury items.