When people imagine scribes and illuminators of Medieval Europe, women with tiny flecks of prized blue pigment in their teeth don’t usually come to mind. And yet, the teeth of a skeleton buried in a modest women's monastery in 1100 CE near Lichtenau, Germany, defies all expectation.
The unmarked grave, labeled B78, hosted a middle-aged woman who lived a life of low physical labor, with no evidence of trauma or infection, and only two molars lost likely due to cavities. The team wasn’t visiting this burial ground to redefine women’s roles in 11th-century rural Germany, they were there to study the plaque preserved in fossilized teeth to learn more about the afflictions and diets of people from this time.
The blue pigment, however, paints a deeper story of this otherwise “unremarkable” skeleton. To delve into this azure mystery, the team took a dental sample from the woman, decontaminated its surface, and disrupted the plaque – also known as dental calculus – via sonication in ultra-pure water. This released fragments and mineral particles, which the researchers slipped under a microscope slide, let dry under controlled conditions, and inspected using light microscopy.
Ultramarine is made by grinding and purifying lazurite crystals from lapis lazuli stones. It “was, by far, the most expensive, reserved along with gold and silver for the most luxurious manuscripts,” noted the researchers. At the time, this pigment produced from lapis lazuli stones was only mined from a single region in Afghanistan and represented a quintessential luxury trade good.
"The growing economy of 11th-century Europe fired demand for the precious and exquisite pigment that traveled thousands of miles via merchant caravan and ships to serve this woman artist's creative ambition," said historian and co-author Michael McCormick of Harvard University.
“Within the context of medieval art, the application of highly pure ultramarine in illuminated works was restricted to luxury books of high value and importance, and only scribes and painters of exceptional skill would have been entrusted with its use,” wrote the team in the study published in Science Advances.