Something old, something new: Diamond’s light illuminates our Anglo-Saxon heritage
With over a hundred graves, the Oakington site is as a substantial 6th-century Anglo-Saxon cemetery. The Anglo-Saxons lived in Great Britain from the 5th century. Originally thought of as Germanic tribes who migrated here from continental Europe, these people amalgamated with Romano-British groups who adopted some aspects of Anglo-Saxon culture and language.
The brooch was probably manufactured from recycled materials. The flecks of different material within the enamel are similar to a Roman enamelling method which used the scrapings from inside metal-working crucibles as a reagent. These results suggest that previously-used glasses and materials were ground together to form a new enamel mixture for this brooch, using a method which is not known amongst the continental Angles or Saxon.
Nonetheless, the style of brooch is undeniable an Anglo-Saxon design. A survey of other Anglo-Saxon brooches that have been unearthed at the Cambridge/Suffolk fen edge also found traces of enamelling, suggesting that this was a much more significant and localised phenomenon than once thought.
What we’re seeing here is a very exciting fusion of Anglo-Saxon art and Roman-British technology. One of the things we didn’t find on our first trip to Diamond was any trace of mercury on the gilded brooch we studied. This was intriguing, because the main theory for how gold was applied to jewellery in Anglo-Saxon Britain is that it involves the use of mercury to make an amalgam. We were lucky enough to be able to come back to I18 to investigate the gilt on three Oakington brooches from different periods in history.”
The results of these later experiments are still being analysed, but they do seem to suggest that mercury was involved in the gilding process in the Anglo-Saxon period.