Conservators at the Prado in Madrid discovered that their copy may in fact be a sister to the original Da Vinci masterpiece after removing black over-painting from the copy, which revealed a Tuscan landscape background similar to the background of the original Mona Lisa, which hangs in The Louvre, the New York Times reported.
It is believed that the copy was painted by one of Da Vinci's students while he was working on the Mona Lisa.
"It is quite possible that Leonardo's assistant met Lisa and may even have been present when she sat for the master," Ana González Mozo, the Prado's technical specialist, told The Daily Mail. "She may also have come to the studio when finishing touches were being applied to the face in the painting."
Because the replica remained hidden beneath the over-paint for such a long period of time, experts believed it was painted long after Leonardo's death, BBC News reported. Conservators used x-rays to study the original drawings underneath, which led them to conclude that the work was in fact carried out at the same time as Leonardo's original.
"You see Lisa's eyes, which are quite enticing, and her enigmatic smile," Martin Bailey, who reported on the discovery for the Art Newspaper, told the BBC. "It actually makes her look much younger."
In the Louvre’s original, Lisa’s face is obscured by old, cracked varnish, making her appear almost middle-aged, the Art Newspaper reported. Because of its delicate nature, the original Mona Lisa cannot be cleaned or restored. The new painting has led experts to speculate that the woman who sat for Da Vinci was in her early 20s, much younger than she appears in the Louvre's original.
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Though both Da Vinci and his famous work are the subject of sensationalist theories, the discovery of the copy has been accepted by experts at both the Prado and the Louvre, the Art Newspaper reported.
Miguel Falomir, the Prado's director for Italian painting, said the copy gives art lovers and experts a chance "to admire the Mona Lisa with totally different eyes," The Daily Mail reported.
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The replica is scheduled to go on view at the Prado by the middle of February.