14C Dating of Lead White in Painted Decorations: The Case of the Queen’s Library at the Palace of Versailles

Radiocarbon dating of lead white has progressed considerably in the last decade. Today, the protocol enables the analysis of various types of samples: pure lead white in cosmetics, ancient and modern paint layers containing lead white and oil, and mixtures of lead white and calcite. However, it has also been shown that the presence of a large amount of calcite in lead white paint can alter the radiocarbon result through contamination with dead carbon. To overcome this problem, careful characterization of samples must be carried out prior to dating. Lead white paint layers from the Queen's apartment at the Palace of Versailles were observed by electronic microscopy and analyzed by Synchrotron X-ray-based diffraction to discriminate the different layers of paint in order to minimize contamination. Chemical analysis and 14 C dating were used to document the implementation of the decorations in Queen Marie-Antoinette's library.