Researchers use X-rays to examine buried Roman coins

Engineers and archaeologists from Southampton University are collaborating with the British Museum to examine buried Roman coins using X-ray imaging technology.

Originally designed for the analysis of engineering parts, such as jet turbine blades, the scanning equipment at Southampton’s µ-VIS Centre for Computed Tomography is being used to examine Roman coins buried in three archaeological artefacts from three UK hoards.

According to the university, the centre’s equipment can scan inside objects, rotating 360º while taking thousands of 2D images, which are then used to build detailed 3D images. In the case of the coins, the high-energy/high-resolution combination of the Southampton facilities allows them to be examined in detail without the need for physical excavation or cleaning.

For those recently scanned at Southampton, it has been possible to use 3D computer visualisation capabilities to read inscriptions and identify depictions of emperors on the faces of the coins.

Southampton University archaeologist Dr Graeme Earl said: ‘Excavating and cleaning just a single coin can take hours or even days, but this technology gives us the opportunity to examine and identify them quickly and without the need for conservation treatment at this stage. It also has potential for examining many other archaeological objects.

‘The university’s Archaeological Computing Research Group can then take this one step further — producing accurate, high-resolution CGI visualisations based on scan data. This gives archaeologists and conservators around the world the opportunity to virtually examine, excavate and “clean” objects.’

The three objects examined at Southampton are a cremation urn containing nine coins, dating from AD282, found in the Cotswolds; an estimated 30,000 Roman coins discovered in Bath, dating to around AD270 and concreted together in a large block weighing more than 100kg; and a small pot dating to the second century found in the Selby area of East Riding in Yorkshire.

Southampton University and the owners of the artefacts have plans to share the scan data with the public, hopefully through future exhibitions and online.