Following the end of Roman rule in Britain, imports of coinage and other precious metals ended abruptly and the existing supply of precious metals such as silver became increasingly scarce as the fifth century progressed. Existing sources of silver were reused and recycled – as the clipping of coinage neatly demonstrates – and silver was mixed with other metals to extend supply. The use and value of these metals would have dramatically changed in the post-Roman period and hoards allow us to examine this shift in greater detail.
To study the composition of the metal artefacts from our hoards, Ellen is carrying out portable X-ray fluorescence analysis (pXRF). pXRF is a quick and non-destructive technique that allows us to determine and analyse the composition of objects in detail. So far, Ellen has carried out pXRF analysis on several artefacts including those from the Bishops Cannings (Wiltshire) hoard now in the collection of Wiltshire Museum Devizes.
Bishops Cannings contains a mixture of precious and non-precious metals and is one of the more unusual hoards. The hoard comprises of more than 7,000 bronze and silver coins, silver jewellery (rings, necklace clasps and bracelets), belt fittings, bowls and various types of beads. One of the key questions raised from the contents of the hoard is the relationship between these different metals and what this tells us about the nature of the economic landscape in Wiltshire at the end of Roman Britain.
The pXRF analysis revealed that all but one of the silver artefacts from the hoard proved to be mostly of high purity (>90% silver). This silver content is far higher than modern sterling silver and tells us that the owner(s) of these objects held considerable wealth. An analysis of the coins from the Hoxne hoard (Guest, 2005) revealed that the silver content of the latest siliquae to enter Britain was also extremely high and the thousands of siliquae in Bishops Cannings further demonstrate the level of wealth present in the hoard.