Published in Chemistry World, 21 Feb 2013
Camille Pissarro’s The Côte des Bœufs, Claude Monet’s Gare Saint-Lazare and Pierre-Auguste Renoir’sLes Parapluies all have one chemical constituent in common: synthetic ultramarine. This famous blue pigment dates back to the early 19th century, but its synthesis has always been shrouded in secrecy. UK chemists have been working to uncover the recipe, which could help in art restoration and identifying forgeries.
Ultramarine has always held an air of mystique. Its natural occurrence in the mineral lazurite is so rare that artists used it only for depictions of their most important religious subjects, such as the robes of the Virgin Mary or Saint Peter. In 1824, however, the Society for the Encouragement of National Industry, a French society promoting technological advance, offered a prize to anyone who could make the pigment for less than 300 francs per kilo. That prize went to the French chemist Jean Baptiste Guimet four years later, and several others went on to develop their own versions. […]
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