Iron Age Pin Cast for the First Time in Two Thousand Years. Research student at the University of the Highlands and Islands Archaeology Institute uses 21st Century technology to unlock the secrets of Iron Age jewellery.
This summer has been an exciting season for the archaeologists working at The Cairns archaeological site on the island of South Ronaldsay, Orkney. For the first time in two thousand years the full extent of an Iron Age broch has been unearthed and further exciting insights into the people who lived there have been discovered.
Initial evidence pointing to metal working on the site was confirmed when around 60 clay mould fragments used for casting bronze jewellery were discovered, scattered in a matrix of rubble in Trench M over a five to six metre area. These objects dated from the First Century to the Third Century AD and were present in a roughly made structure that was used only briefly – judging by the thin layer of deposit present in the trench. These objects were extremely fragile, but after cleaning, it was clear that a negative image of a delicate, ring headed pin was present in the clay of one mould.
How wonderful would it be if we could re-create this Iron Age pin? To see it as the people who lived in the broch two thousand years ago would have seen it? To experiment and use it as those people would have used it? But further, to use the object in research and teaching, knowing that it was cast from an original mould? But there was a problem…the moulds were too delicate to use in any metal working process.
However, following much discussion, Ben Price – a postgraduate student studying at the University of the Highlands and Islands Archaeology Institute – decided to accept the challenge and use his expertise in computer modelling to re-create the pin in bronze; the original metal used to create these objects. After further discussion and guidance from Martin Carruthers, Master Programme Leader, Ben decided to use the opportunity to make the re-creation of the pin the subject of his Masters Degree dissertation and so use the research to feed back into the teaching at The Archaeology Institute – a particular strength of The Institute.
Using 21st Century 3D rendering technology, Ben photographed and scanned the original Iron Age clay moulds into a computer and created a digital 3D image on the screen. This in itself was exciting as the delicate details of the projecting ring headed pin could be clearly seen emerging from the screen. A 3D model of the resultant pin was created on screen by using the detailed surfaces of the moulds.
The pin model was then sent off to be 3D printed in wax and then used to cast in bronze using the lost wax method.
Archaeologists are used to examining metal objects that have been in the ground for thousands of years, but this process gave archaeologists a view that would have only been available to the original pin maker.
No-one was prepared for the wonderful object that emerged from the casting process. It was an object of wonder, and left everyone speechless for a few moments. It was bright and heavy and extremely tactile. It was an object that would obviously have been treasured and would have been striking as a piece of jewellery.
Martin Carruthers, Masters Degree Programme Leader, said, “This process gives us a unique and exciting insight into the objects that the people of The Cairns actually experienced and used over two thousand years ago. You can see the imperfections and the work involved and it also proves that moulds were made using an object. The process also opens up many possibilities in terms of experimental archaeology in addition to educating the public at large. The object also in a way opens up the possibility that the Iron Age was full of colour and bright objects that were treasured….perhaps they were not so dissimilar to people of today!”