What is the description of the Mona Lisa by Leonardo Da Vinci?

Was the Mona Lisa at the Prado Museum painted by Leonardo Da Vinci himself or one of his pupils?

• The famous Virgin of the Rocks was painted twice. Even though, the second time, Da Vinci didn't paint the whole project. When you look closely into the new Mona Lisa, you see an exact copy of the Tuscan landscape, 2/3 view and the usual Da Vinci light and shadow experiment and looks like to have a more perfect, pure and vibrant colors. If the painting is done same time  or upstaged, what are the chances of a pupil copying unfinished painting or using the same technique as Da Vinci?

• Answer:

  That’s a very good question that requires a bit of a complicated answer.     This interesting portrait was first referred to in the 1666 inventory in the Galleria del Mediodia del Alcazar as ‘mujer de mano de Leonardo Abince’ (‘Leonardo da Vinci’s handy woman’).   There has never been any suggestion that the Prado copy was painted by Leonardo. Bruno Mottin, the head conservator at the Centre de Recherche et de Restauration des Musées de France, is reported as believing that it was likely painted by one of Leonardo’s favourite apprentices, for example, Salai, or Melzi, There is no real evidence that Salai ever had the talent to paint a portrait as exquisite as this version, and Francesco Melzi was only 15 when he first met Leonardo, in 1506. In all likelihood, Melzi would not have had sufficient experience to have painted this copy, in parallel with Leonardo, while they were in Rome from 1513 to 1516. Melzi did eventually become an accomplished artist in his own right, but if the Prado ‘Mona Lisa’ is his work, then it could only have been completed some years after Leonardo’s death. It is also opined that it could have been executed by one of Leonardo’s Spanish students, who returned with it to Spain, and perhaps even completed it in Spain. Another theory is that the painting was taken by the Spanish when they sacked Rome in 1527.