A number of artefacts ranging from flint tools to Neanderthal bones from around Verona (Italy), have begun to turn blue, causing worry and consternation, and potentially legal action.
     The objects were moved from an eighteenth century castle, where overflow from Verona's Natural History Museum was stored, to a former arsenal, in 2007-2008. The castle was sold by the local authority, but the proceeds of the sale, which were intended to refurbish the arsenal and make it a suitable home for all the museum's collections, were later reallocated.
     Laura Longo, the curator of the collection, who noticed the blue phenomenon on flint tools when she visited the relocated artefacts, gave samples to geoarchaeologist Gilberto Artiolo of the University of Padua, as well as reporting the problem to Vincenzo Tine, the area representative of the ministry of culture in Venice, and others, including the department of the police responsible for crimes against cultural heritage. Artiolo's analsyis suggested that hydrocarbons from petrol and weapon lubricants present during the building's use as an arsenal and found in the samples and their packaging may be playing a role in creating the blue sheen, reacting to form some kind of durable pigment.
     A petition demanding the immediate relocation of the artefacts is being sent to Italy's culture minister Sandro Bondi. It also calls for an assessment of the damage and an investigation into who is responsible for placing the objects in danger. It may turn out that the arsenal had not been checked for potential pollutants, which may make Verona's local authority culpable under Italy's laws on antiquities.  
     While Tine notes that very few of the millions of objects in the collection have been affected, and suggests that they can be restored, others are more worried. Artioli warns that "paleontologists will never be able to do any meaningful analysis from a chemical point of view" and notes that the more porous bones and pottery will be worse affected than stone objects. DNA analysis of the Neanderthal remains is one method of potentially reconstructing their movements before they died out.

Source: Nature (15 July 2010)