A compositional study of Cypriot bronzes dating to the Early Iron Age using portable X-ray fluorescence spectrometry (pXRF)

Abstract

A collection of 157 copper alloy artefacts from the necropolis of Palaepaphos Skales, located in south-west Cyprus, dating to the 11th-8th centuries BC, was studied and chemically analysed with a handheld pXRF instrument to determine the alloy type that was used for their production. The collection consists of Cu–Sn binary alloys. The relative concentration of the two metals seems to have been determined by the type of artefact the alloy was used to produce. The results also imply that fresh rather than recycled metal was used. The majority of the artefacts are made of a bronze with an average tin content of 8.1 ± 2.2%. There is, however, a group of objects with a characteristic golden surface, under the patina, which was found to have a significantly higher tin concentration, that averages 18.6 ± 2.8% Sn. The lead content in the assemblage ranges from 0.1 to 2.6%. Because lead concentration in local Cypriot ores is unusually low, its presence is interpreted as a deliberate addition even at these low concentrations. The iron content ranges from 0.1 to 1.4%, while zinc is present only in 20 artefacts, exhibiting a concentration range of 0.2–1%. Both elements are believed to be non-intentional additions to the alloys, resulting from the smelting process and originating in the copper ores (which are sulphidic and closely associated with sphalerite). Arsenic is detected in 25 artefacts, in a concentration of 0.2%. The limited amount of arsenic in only a few of the artefacts under study may be the result of the use of polymetallic ores from the area of Limassol Forest, the only Cypriot ores where low amounts of arsenic can be detected, or can be interpreted as evidence for the possible use of recycled metal deriving from artefacts dating to the Early and Middle Bronze Age. The present study provides significant evidence concerning the continuity of the use of bronze with high tin content in the area of Palaepaphos throughout the Early Iron Age.