Leonardo da Vinci is known for using less traditional painting techniques and mediums in his works, and we are still making new discoveries about them; The latest is the mixture of toxic pigments underlying the Mona Lisa brushstrokes.

Researchers from France and the UK examined a small micro-sample taken from a hidden corner of the Mona Lisa, using a variety of X-ray diffraction and infrared spectroscopy techniques to identify the substances involved.

As expected, the team found not only oil and lead whites, but also the rare compound plumbonacrite (Pb).₅(CO₃)₃ O(OH)₂). Plumbonacrite forms when petroleum and lead(II) oxide (or PbO) react together; this suggests that the latter compound was used by da Vinci.

“Leonardo was probably trying to prepare a thick paint suitable for covering the wood panel of the Mona Lisa by treating the oil with a high percentage of lead (II) oxide, PbO,” the researchers wrote in the published paper.

The same compound PbO was found in several microsamples taken from the surface”“Secret Dinner”, another famous da Vinci painting. However, the only reference to PbO in the Italian artist’s works was related to skin and hair products.

Although it is not included in his writings, it appears that da Vinci used this lead(II) oxide as a ground layer. This is something that has been hypothesized before, but now we have more direct evidence for it.

It is believed that Da Vinci heated lead(II) oxide and dissolved it in linseed or walnut oil, creating a mixture that was thicker and faster-drying than traditional oil paints; a recipe that has since been used by others. artists

The same substance plumbonacrite was also found in Rembrandt’s painting “Night Watch” It was created in 1642 – almost a century and a half after the Mona Lisa. This suggests that the Dutch master used a technique similar to da Vinci’s.

This discovery is another example of how modern analytical techniques reveal new discoveries about historical artifacts. Advanced 3D imaging has previously been used to examine another Da Vinci painting. Savior Mundi.

This is also a testament to the enduring creativity of Leonardo da Vinci, a man who achieved greatness not only in his paintings but also in many other fields such as mathematics, chemistry and engineering.

“He was someone who loved to experiment, and each of his paintings is technically completely different,” chemist Victor Gonzalez of the Institute for Chemical Research in Paris, France, told the Associated Press.