The crown of French Empress Eugenie was left crushed after being dropped by fleeing thieves during the raid at the Louvre last October - but is nearly intact and can be fully restored, the museum has said.
Raiders stole an estimated 88 million euros (£76m, $104m) in jewels but left the diamond-studded headpiece belonging to the wife of Napoleon III on their escape route.
The museum has issued the first photographs of the crown since the theft, stating it had been left badly deformed after the thieves tried to remove it through a narrow hole they sawed in its glass display case.
The crown is missing one of eight golden eagles that adorned it but retains its 56 emeralds and all but 10 of its 1,354 diamonds.
The museum added the 19th Century crown would be restored to its original state without the need for reconstruction. An expert committee led by the museum's president Laurence des Cars has been selected to supervise the restoration.
The heist took place on 19 October and involved the gang using a stolen vehicle-mounted mechanical lift to access the Galerie d'Apollon (Gallery of Apollo) via a balcony overlooking the River Seine.
Two of the thieves got inside by cutting through a window with power tools. They then threatened the guards, who evacuated the area, and cut through the glass of two display cases housing jewelry once belonging to French royalty or its imperial rulers.
Prosecutors revealed the thieves were inside for less than four minutes before making their escape on two scooters waiting outside. Four male suspects have been arrested, but the mastermind behind the raid has not yet been found.
Additionally, seven other pieces of jewelry, including a diamond-studded tiara that belonged to Eugenie and various necklaces, earrings, and brooches, remain missing.
