The Composition and Microstructural Variation of the Bronze Age Metal Ornaments from Lower Silesia (South‐West Poland): Chemical Analytical and Archaeological Aspects

Metal ornaments from unetice (Mierczyce, Tomice, Jordanow and Opatowice) and Urnfield culture (Szprotawa, arek and Wrocaw erniki) sites in south-west Poland are made of bronze of varying composition, with the exception of the early Bronze Age Przecawice site, where the copper items are found in graves from stages III/IV. The combined XRF and electron microprobe study of 37 ornaments (mostly pins) shows that those excavated from unetice culture graves usually consist of cored dendrites, plus a Sb-rich phase in some. The copper objects from Przecawice correspond in composition to the East Alpine Copper or to the osenring copper and were produced from fahlore. Those from the Urnfield culture sites consist of homogeneous bronze. The unetice culture ornaments were produced with little control of the effect of varying bronze composition on its microstructure. The results of XRF analyses of heterogeneous metal artefacts vary depending on the proportion of phases in the analysed site, and should be combined with micrometre-scale analytical data and microstructural information yielded by electron microprobe methods. The same refers to deeply weathered or corroded objects made of homogeneous metal, which contain irregularly dispersed decomposition products.