Scientists at Loughborough University are carrying out trials of a new chemical blueprint technique that could help crack down on the growing issue of stone theft.
The results of a UK heritage crime survey carried out by the university’s department of social sciences indicate that stone is now the third most popular target for thieves at heritage sites behind copper and lead.
The survey of heritage professionals found that 31% felt that lead was under most threat of theft, 21% named copper, and 12% identified stone as being most at risk.
The issue was recently discussed in a parliamentary debate, with MPs referring to multiple cases of organised gangs stealing paving stones and “topping” stone from dry stone walls.
Unmarked stone is hard to trace and identify once it has been sold, an issue that Dr Paul Kelly believes can be helped with a technique being trialled by the university’s chemistry department.
Gangs are stealing paving stones and “topping” stone from dry stone walls
According to Kelly the procedure involves extracting a chemical blueprint from stone using a gelatine sheet (the sort normally used to lift developed fingerprints or footprints). The sample is then scanned using laser induced breakdown spectroscopy (LIBS) to determine the original geographical location of stone.
Kelly said: “We believe our non-invasive technique could provide a much-needed link between suspected stolen stone and its original geographical location, but it is very early days.
“This technique of lifting a sample from the surface of stone and scanning it could ultimately lead to us feeding the results into a national database, providing an indication of where geographically that sample came from. This can be done by comparing the stone samples with other stone located across the country and could prove to be a useful point of reference for those tackling stone theft.”
The technique has already been proved effective for metal theft detection.
"We believe our non-invasive technique could provide a much-needed link between suspected stolen stone and its original geographical location, but it is very early days."
Dr Paul Kelly, Loughborough University
There is a growing awareness in the industry over the need to verify the source of materials and ensure that parties along the supply chain are acting ethically.
Professor Jacqueline Glass, of the school of civil and building engineering at Loughborough University, explained that innovations like stone blueprinting could make a really useful contribution to assurance and verification in construction supply chains.
Glass told Construction Manager: “What we are seeing here is an important technical development that could be deployed to help companies be more confident that they know where their materials come from.
“With growing concerns about the risk of environmental and ethical breaches in construction supply chains, we would be keen to see manufacturers and merchants making more use of ‘fingerprinting’ to deliver greater confidence to their customers and stakeholders.
“Loughborough University is championing the greater awareness and adoption of responsible sourcing in construction through its network APRES [the Action Programme on Responsible Sourcing] which I’m leading.”
