Late Bronze Age Caucasian daggers made of arsenical bronze… and tin bronze

Several Late Bronze Age Caucasian daggers were studied in order to evaluate their chemical composition and microstructure. The daggers derive from North Ossetia-Alana, Russia, and are since the 1880ies in the Natural History Museum Vienna. The arsenical bronzes are characterised by a high amount of arsenic (2-5wt.%), as are the tin bronzes by high amounts of tin in the alloy (10-17 wt.%). However, most of the dagger blades studied are ternary Cu-As-Sn alloys. Two arsenical bronze blades show intense segregation of γ-phase along the blades’ surface and the grain boundaries (remember my article on inverse segregation of arsenical bronzes!); some of the arsenical bronze blades also show eutectic, which hardness could be measured. One dagger was made of a tin-bronze blade and an arsenical bronze hilt (see Figure on the bottom). The article will include chemical analyses, metallographic studies, hardness measurements, and Pb-isotope analyses. I’ll keep you updated once it’s published!

Late Bronze Age dagger from Koban, Republic of North Ossetia-Alania, Russia. The colour of the hilt was silverish while the blade had a warm, golden-like colour. The hilt contains about 9.8 wt.% arsenic and no tin, while the blade contains 10.1 wt.% tin, and no arsenic. Today, the dagger is very much corroded, so the original colours of the metals are not any more visible (Photograph © Naturhistorisches Museum Wien; inv.no. 41.268).

Late Bronze Age dagger from Koban, Republic of North Ossetia-Alania, Russia. The colour of the hilt was silverish while the blade had a warm, golden-like colour. The hilt contains about 9.8 wt.% arsenic and no tin, while the blade contains 10.1 wt.% tin, and no arsenic. Today, the dagger is very much corroded, so the original colours of the metals are not any more visible (Photograph: M. Mödlinger, © Naturhistorisches Museum Wien; inv.no. 41.268).

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