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 attempted to remove it through a narrow hole 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 noted that 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, had been selected to supervise the restoration.
The heist, which took place on October 19, saw the gang use a stolen vehicle-mounted mechanical lift to gain access to the Galerie d'Apollon via a balcony near the River Seine.
Two of the thieves cut through a window with power tools, threatened the guards, and cut through the glass of two display cases containing jewellery that once belonged to French royalty. They were inside for less than four minutes before escaping on scooters waiting outside.
While police have arrested four male suspects alleged to be involved in the heist, the mastermind remains at large. The other seven stolen items, which include a diamond-studded tiara and several necklaces, earrings, and brooches, are still missing.
