Small flecks of blue inside of the mouth of a medieval skeleton are raising big questions about women's role in ancient religious manuscripts.

The skeleton of a woman, believed to be from the 11th or early 12th century, was discovered buried near a women's monastery in western Germany with an expensive pigment staining her lower jaw, according to a research article in the peer-reviewed scientific journal Science Advances. The pigment, made from lapis lazuli stones found in Afghanistan, was as valuable as gold at the time.

The pigment was used to illustrate luxury books and religious texts — and authors were long thought to be monks, not women. Before the 12th century, less than 1 percent of books were attributed to women, according to the research article.

Researchers believe this 45- to 60-year-old woman, who might have been a nun, could have been a scribe or book painter of highly-respected manuscripts. She could have obtained the blue stains in her mouth from the practice of licking her brush to make a fine point.

Anita Radini, who coauthored the study, told USA TODAY if the woman repeatedly put a pigmented brush in her a mouth, the blue particles could easily have become embedded in her plaque and tarter.

"This woman represents the earliest direct evidence of ultramarine pigment usage by a religious woman in Germany," the article states.

Other theories researchers believe are less likely: She was involved in the preparation of the pigment, she ate powdered lapis lazuli as a form of medicine or she regularly kissed painted figures as a religious practice.

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