|Zosia at the X-ray table|
X-radiography is a form of electromagnetic radiation that allows us to create images showing features and details invisible to the naked eye. It is important to X-ray metal objects to create visual record of how an artefact was made, as well as its shape and condition. X-rays can also help with identification if an artefact is hidden by layers of corrosion or concretion, and are an excellent means of scientific examination without affecting or destroying archaeological finds in any way.
For these reasons, artefacts are often X-rayed as part of the conservation process. The examples used for the handling table are all from the excavation of the Thermae Spa in Bath city centre, and were chosen because the archive contained copies of their X-rays.
|X-ray of a Roman coin from the SPA98 excavations|
Decorative surface details such as inlay or enamel can also be seen through X-ray, and non-ferrous coatings become visible due to the difference in density between the metals.
The English Heritage guidelines on the X-radiography of archaeological metalwork (http://www.helm.org.uk/upload/pdf/X_Radiography.pdf?1331775979 ) has a number of beautiful examples that show exactly how valuable X-raying metal artefacts can be, including images of inlay details and coin identification. I really recommend browsing through it, even if it is just to marvel at the lovely pictures!
Zosia - Collections Intern