High-tech X-Ray Spots Unusual Element in Ancient Manuscript
Louisa Smieska and Ruth Mullet were surprised to find barium in the azurite blues of medieval illuminated manuscript pages. Azurite, a soft, deep blue copper mineral produced by weathering of copper ore deposits, has been recognized since ancient time. However, the trace element barium is more often associated with modern paints, and, according to the researchers, has never been reported in illuminated manuscripts before.