Clues to long-lost Leonardo da Vinci masterpiece found

UC San Diego researchers say they have found tantalizing clues to a mystery that has puzzled the art world for five centuries: the fate of a lost masterpiece by Leonardo da Vinci.

Samples taken from a stone wall hidden behind a fresco that adorns the Palazzo Vecchio in Florence, Italy, appear to contain a black pigment similar to the one Leonardo used on his masterpiece “Mona Lisa,” the researchers announced Monday. Other samples contained a red lacquer-like substance and a beige material apparently applied with brush strokes — both consistent with the presence of a painting.

The findings are the latest in a quest to discover whether Leonardo’s missing masterpiece, “The Battle of Anghiari,” might have been intentionally spared by a fellow artist, Giorgio Vasari, when Vasari decorated the palazzo with his own frescoes.

Experts have long believed the Leonardo was destroyed a few decades after it was abandoned, unfinished, by the Renaissance master. And Monday’s announcement left some skeptical because the results have not been independently verified.

But Maurizio Seracini, the UC San Diego researcher who has led the search for the Leonardo for three decades, called the findings “very encouraging.”

“The evidence does suggest we are searching in the right place,” said Seracini, director of UC San Diego’s Center of Interdisciplinary Science for Art, Architecture and Archaeology.

Seracini, whose current work is a partnership with the National Geographic Society and the city of Florence, acknowledged that the results were preliminary. “There is still a lot of work to be done to solve this mystery.”

The stone wall where Seracini has focused his research is in the Hall of 500, the seat of government in Florence. In the early 1500s, Leonardo and his rival Michelangelo Buonarroti were commissioned to decorate the hall with scenes of Florentine military victories.

Michelangelo completed only a sketch of his scene before being called back to Rome to paint the Sistine Chapel. Leonardo completed a central scene but abandoned his painting when his experimental technique — oil painted on a base of plaster mixed with wax or linseed oil — failed. In some areas, the colors ran together and the plaster separated from the wall, according to contemporary accounts.

Still, both works were hailed as masterpieces.

Today the stone wall on which Seracini thinks Leonardo worked is hidden behind a large fresco painted by Vasari, who was asked to decorate the room a few decades after Leonardo and Michelangelo abandoned their scenes.

Vasari, considered a father of art history for his biographies of Renaissance painters, was an admirer of Leonardo, and he praised the “incredible skill” demonstrated in the master’s incomplete scene. Some have thought it would be out of character for Vasari to have destroyed Leonardo’s work to make way for his own.

The theory took on new life in recent years as Seracini’s team used high-tech analyses to find a narrow gap between Vasari’s fresco and the building’s original stone wall. With the help of ultrasound, infrared, ultraviolet, microwave and other imaging technologies, they were able to virtually peel away layers of pigment, plaster and brick, stripping the centuries-old wall to its bones and narrowing the potential locations of Leonardo’s work.

The search stirred controversy last fall when Italian conservation authorities let Seracini’s team drill holes through Vasari’s fresco to insert tiny probes into the wall. The holes were made in areas where Vasari’s original paint was already missing.

Nevertheless, hundreds of leading art historians from Europe and the United States decried Seracini’s work, saying that he was destroying a known masterpiece in a futile quest to find a missing one.

It is those probes that revealed the evidence announced Monday, including beige marks that, according to a news release from National Geographic, “could only have been applied by a paintbrush.”

Seracini said Monday’s announcement was a vindication of his quest.

His critics are not convinced.

“The results are from a private lab and have not been verified by any third party,” said Tomaso Montanari, an Italian art historian who launched a petition to stop the work. “These data do not change the situation one iota.”

The National Geographic Channel will air a documentary about the search Sunday.

jason.felch@latimes.com