Stone-faced chemists

York Minster, the 15th century limestone cathedral, has over the centuries suffered much erosion as a result of weathering and pollution. During this time restoration work has been done, some of which has been more successful than others. Now, in what is the latest phase of such work, archaeologists from the University of York have teamed up with chemists from the University of Cardiff in an attempt to restore the east front of the cathedral.

By using a range of X-ray techniques, the chemists are providing detail on the microscopic composition of the limestone, historical mortars and the decay products. This information should give the conservators the edge when it comes to deciding how to treat the stone, and importantly should ensure that in their efforts to preserve history they do not cause further damage.