PARIS (AP) — The “Mona Lisa” has ... the ground layer of ‘Mona Lisa,’” he said in an interview with The Associated Press. Specifically, the researchers found a rare compound, plumbonac ...

The base layer of Leonardo’s mural “The Last Supper” was also found to have the same chemical makeup as the “Mona Lisa” even though the mural was painted on a wall, according to the study.