X-rays of the “Mona Lisa” reveal a new secret about Leonardo da Vinci’s masterpiece

Mona Lisa” He gave away another secret.

Using X-rays to look at the chemical composition of a tiny dot of a famous work of art, scientists have gained new insight into the techniques Leonardo da Vinci used to paint his pioneering portrait of a woman with a brilliant, enigmatic smile.

search, Published Wednesday In the Journal of the American Chemical Society, he suggests that the famously curious, learned, and innovative Italian Renaissance master may have been in a particularly experimental mood when he began work on the “Mona Lisa” in the early 16th century.

The oil paint recipe Leonardo used as a base layer for the poplar wood painting appears to have been different from the Mona Lisa, with its distinct chemical signature, a team of scientists and art historians in France and Britain have discovered. .

“He was a person who loved to experiment, and each of his paintings was artistically very different,” said Victor Gonzalez, lead author of the study and a chemist at the National Center for Scientific Research, France’s top research body. Gonzalez studied the chemical composition of dozens of works by Leonardo, Rembrandt and other artists.

“In this case, it’s interesting to see that there was actually a specific ground layer technique for the Mona Lisa,” he said in an interview with The Associated Press.

Specifically, the researchers found a rare compound, plumponacrite, in the first layer of Leonardo’s paint. Gonzalez said the discovery confirmed for the first time what art historians had previously assumed: that Leonardo likely used lead oxide powder to thicken the paint and help dry it when he began working on the painting that now peers out from behind the protective glass in the picture. Louvre Museum in Paris.

Carmen Bambach, an Italian art specialist and curator at the Metropolitan Museum of Art in New York, who was not involved in the study, called the research “very exciting” and said any new scientifically proven insights into Leonardo’s drawing techniques are “very important news for us.” The art world and our larger global community.”

Finding plumponacrite in the “Mona Lisa” testifies to “Leonardo’s spirit of passionate and constant experimentation as a painter — that is what makes him both timeless and modern,” Bambach said via email.

The patch of paint from the base layer of the Mona Lisa analyzed was barely visible to the naked eye, no larger than the diameter of a human hair, and came from the upper right edge of the painting.

Scientists have looked at its atomic structure using X-rays at a synchrotron, a large machine that accelerates particles to almost the speed of light. This allowed them to reveal the chemical composition of the stain. Plumbonacrite is a byproduct of lead oxide, allowing researchers to say with more certainty that Leonardo most likely used the powder in his paint recipe.

“Plumbonacrete is actually an imprint of his recipe,” Gonzalez said. “It’s the first time we can confirm this chemically.”

After Leonardo, the Dutch master Rembrandt may have used a similar recipe when he was painting in the 17th century; Gonzalez and other researchers have previously discovered plumponacrite in his work as well.

“It also tells us that these recipes have been passed down for centuries,” Gonzalez said. “It was a very good recipe.”

Leonardo is thought to have dissolved the orange-coloured lead oxide powder in linseed or walnut oil by heating the mixture to make a thicker, faster-drying paste.

“What you’ll get is a very beautiful, golden-colored oil,” Gonzalez said. “It flows like honey.”

But “Mona Lisa” — which the Louvre said is a portrait of Lisa Gherardini, the wife of a Florence silk merchant — and other works by Leonardo still have other secrets to tell.

“There are lots and lots of things to discover for sure. We’re barely scratching the surface,” Gonzalez said. “What we say is just a small building block of knowledge.”