Technique could provide a means of tracing stolen, unmarked stones

A combined laser and chemical ‘blueprinting’ technique could help crackdown on the growing problem of stone theft from heritage sites, according to researchers at Loughborough University, UK. There has been a significant increase in stone thefts in rural parts of the UK in recent years, to the extent that it prompting the problem to be recently debated in the House of Commons. A recent survey indicates that stone has become the third most popular target for thieves at heritage sites in the UK, just behind copper and lead.

Currently, a major barrier that the police face when working on stone theft cases is trying to trace unmarked stone after it’s already been sold. This new technique, which involves extracting a chemical 'blueprint' from stone using a gelatine sheet and then scanning the sample using laser induced breakdown spectroscopy (LIBS), offers hope of helping to solve such crimes. In the past, the team has successfully demonstrated that this combination of LIBS and gelatine lift can detect metal theft and create a map of metal traces left on a suspect’s hands.

The approach that the team is testing could ultimately lead the researchers to enter their results into a national database, providing an indication of where that sample originated from. This could offer a useful point of reference from which to tackle stone theft.