Rare 9-ct Pink Diamond on Display 100 Years after Theft

(IDEX Online) - A rare nine-carat pink diamond that was stolen from a French chateau nearly 100 years ago went on public display this week.

The pear-shaped Grand Conde diamond was stolen during an overnight raid at the Chateau de Chantilly in northern France, about 40 kilometers (25 miles) north of Paris, in October 1926.

It was hidden inside a hollowed-out apple, according to accounts of the theft, and was recovered several weeks later after a hotel maid took a bite of the fruit.

The diamond went on display at the Conde Museum, inside the chateau, on October 17, 2026, and is scheduled to remain there until January 3, 2027, marking a century since the robbery.

The exhibition is being organized by the museum in partnership with L'ECOLE, School of Jewelry Arts, with support from Van Cleef & Arpels. It includes previously unseen archival material, historical photographs, press cuttings and documents relating to the investigation and recovery.

A major research project combining historical investigation and gemological analysis has also revealed new details about the stone. Scientists found that its pink color results from physical characteristics rarely observed in diamonds, offering new insights into its exceptional properties.

The diamond was first documented in 1740 in an inventory drawn up following the death of Louis Henri de Bourbon, Prince of Conde, and became one of the most important gems in the Conde collection.

It later entered the collection of Queen Marie-Amelie of Bourbon-Sicily, who intended it for her grandson, Louis of Orleans. Following his premature death, the jewel passed to his father, Henri d'Orleans, Duke of Aumale.

The duke bequeathed the diamond, along with the Musee Conde collection, to the Institut de France, which owns the Chateau de Chantilly. The diamond's exact origins remain unknown.