The focus of this study is to detect any similarities – or lack thereof – between the alloys of different types of oval brooches from the later Iron Age in Scandinavia. The study is furthermore concerned with how the alloys and the typologies can be mutually complimentary to one another in regards to dating or determining the age of specific oval brooches. For this purpose X-ray fluorescence (pXRF) was used on five different items deriving from Birka, Vendel and one of unknown context.

The results indicate continuity with earlier studies regarding copper alloys with contents of zinc, and that this study’s brass brooches may have been produced in this alloy for its gold-like appearance. A higher level of lead can be found in the younger brooches, therefore indicating that tortoise brooches of a later date may contain more lead than their earlier counterparts. Furthermore, the study shows that brass may be mistaken for gold, and it raises questions about the use of metal originating from native copper sources.

This study is a part of the Birka Black Earth Harbour project.