Early Roman copper-alloy brooch production: a compositional analysis of 400 brooches from Germania Inferior

We present here a compositional study of a large number of copper-alloy brooches, undertaken in 2014 using Handheld X-ray Fluorescence Spectrometry (HHpXRF). The brooches, which come from the area of Nijmegen, date from the Late Iron Age until the 2nd c. A.D. Our aim is to explore the ways in which artefact production was organized both in the context of Roman centres and in the countryside. The link between alloys and workshop organization will be elucidated before the methodology and results are presented. The results will then be discussed, leading to the formation of several hypotheses regarding the organization of workshops that produced metal artefacts. Scientific interest in the composition of ancient artefacts has existed for well over two centuries. Roman brooches in particular have been in the forefront of this research both because of their ease of categorization and because they are found in large numbers on archaeological sites. Much work has been done on how they were made and on the technical choices available to the craftsmen. In particular, the choice of alloying agents (tin, lead, zinc) added to copper demonstrated a complex relationship between composition and typology, especially in the debate over Roman or local production. The technological restraints imposed on these artefacts by different alloy ratios have been studied in some detail, especially in terms of casting in liquid form, into a mould, or being wrought through beating with a hammer.