Researchers at the Rijksmuseum, the University of Amsterdam, VU Amsterdam and the European Synchrotron Radiation Facility (ESRF) have developed a method that reveals how the costly pigment ultramarine was prepared from the semi-precious stone lapis lazuli. Thanks to X-ray examinations of paint samples, they can now look back more than four hundred years to determine whether the blue stones were brought to a red heat during the pigment extraction process. The results, recently published in the leading journal Science Advances, also help to cast light on the disastrous “ultramarine disease.”
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Source: Phys.org