Identification by Raman microscopy of anachronistic pigments on a purported Chagall nude: conservation consequences

A painting purported to be by the artist Marc Chagall has been examined using Raman microscopy to check on its proposed execution date of 1910. The analysis shows that, due the presence of phthalocyanine pigments, the painting cannot have been created prior to c.1938. Transport of the painting to the Chagall Committee in France for inspection has led to their declaration that the painting is a forgery. Under French law the painting is required to be destroyed rather than retained for other forensic examination; the consequences for preservation of such items is of paramount importance, as is the need for auction houses to carry out analyses prior to auction.