The Pink Diamond Returns to Chantilly With Its Secrets Re-examined
A diamond stolen from the Château de Chantilly nearly a century ago is returning to public view with new scientific research behind it. Known as the "Grand Condé," the pink diamond weighing just over 9 carats will go on display at the Musée Condé from 17 October 2026, the focus of an exhibition devoted to its history, provenance and physical characteristics.
The stone has been documented in the collections of the Princes of Condé since the 18th century, though for most of that time its story rested on inventories and archival paperwork alone. The Château de Chantilly and L'ÉCOLE, School of Jewelry Arts, set out to test that record against science, cross-checking the archives with gemmological analysis of the stone's rare pink colour.
Emmanuel Fritsch, professor emeritus of physics at the University of Nantes, led the gemmological study alongside specialists from the French Gemmological Laboratory. Their analysis identified the structural characteristics behind the diamond's colour — new scientific ground for one of France's most storied gemstones.
Louis Hersent, Portrait of Queen Marie-Amélie, c. 1835, © RMN-Grand Palais, Gérard Blot
An inventory drawn up after the death of Louis Henri de Bourbon, Prince of Condé, gives the earliest known record of the diamond. It later entered the collection of Queen Marie-Amélie of Bourbon-Sicily before passing to Henri of Orléans, Duke of Aumale, whose bequest formed the foundation of the Musée Condé.
In 1926, the diamond was stolen during a burglary at Château de Chantilly. After several weeks of investigation, it turned up hidden inside an apple, before being returned to the collection.
The exhibition, running from 17 October 2026 to 3 January 2027 in the Gem Cabinet and Gallery of Psyche, will follow the diamond's passage through royal collections, museum archives and now the laboratory. Documents, photographs, investigation records and research imagery will sit alongside the stone itself.
