Grand Condé Diamond Goes on Show 100 Years After the Apple Theft

The Grand Condé diamond, a 9.01-carat pink stone stolen in 1926 and found hidden in an apple, is on public display at the Château de Chantilly from 17 October 2026 to 3 January 2027. It is the first time the stone has been shown since that theft, almost 100 years ago to the day.

For anyone who buys, sells or simply loves coloured diamonds, it is a rare chance to see a historic natural pink in person. It is also a useful moment to ask why pink diamonds command the prices they do, and what a buyer in Hatton Garden should check before paying for one.

This piece covers the exhibition, the theft, what the official record says about the stone, and the questions worth asking a jeweller. For the longer background, our history of pink diamonds goes back much further than 1926.

Where and when can you see the Grand Condé diamond

The Grand Condé is on show at the Musée Condé, inside the Château de Chantilly, about 50km north of Paris, from 17 October 2026 to 3 January 2027. Entry is included in the timed one-day château ticket; event listings give €18 full price and €14.50 reduced, so check the price when booking.

The exhibition, called "The Pink Diamond" in English, is set in the Gallery of Psyché and the Gem Room, according to the château's exhibition page. The château opens every day except Tuesday, from 10am to 6pm. The Musée Condé organised the show with L'École des Arts Joailliers, supported by Van Cleef & Arpels, and its chief heritage curator, Mathieu Deldicque, curated it.

The stone is not shown on its own. According to the museum, the results of the scientific study carried out on the diamond appear in the exhibition alongside archive material about its history and the 1926 theft that has not been shown before.

One practical point makes the trip the only option. The French Ministry of Culture's collection record for the stone marks it as barred from loan or deposit. It will not travel to London, or anywhere else, so seeing it means going to Chantilly.

From London the château is a day trip: Eurostar to Paris, then a regional train north. We have not checked journey times for this piece, so plan the route on the day.

How the Grand Condé was stolen and found in an apple

The story of the Grand Condé diamond sounds invented. According to the museum, it is not.

During the night of 11 to 12 October 1926, thieves took the diamond from the Musée Condé. They hid it inside a hollowed-out apple, and French press accounts of the case say they never managed to sell it. The stone was recovered weeks later, in December 1926, in a Paris hotel, when, as the BBC tells it, a hungry maid bit into the apple. Mathieu Deldicque, who curated the exhibition, told the BBC that the account was widely covered by the newspapers of the day.

The detail that matters more for a jeweller is what happened next. Since then, Galerie magazine reports, the museum has shown visitors a replica. The original has stayed out of public view for close to a century, which is why this exhibition is drawing press from Paris to London.

Security is the obvious question. Deldicque has been asked whether the show tempts fate, after a year of thefts from European museums, including the daylight robbery of jewels from the Louvre in Paris. He declined to say how much the diamond is insured for. Fair enough. He did say that detailed scientific study of the stone has made it uniquely identifiable, and the results of that analysis form part of the exhibition.

What the official record says about the stone

The legend says the diamond decorated the pommel of a cane belonging to Louis II de Bourbon-Condé, the 17th-century general known as the Grand Condé. The official record is more careful.

The Ministry of Culture's Joconde entry describes a pear-shaped diamond of 9.01 carats, measuring 20.2mm by 14.2mm and 4.8mm deep, with a unique, slightly orangey pink tint. It says the stone "would have" belonged to the Grand Condé, the conditional tense a museum uses for a tradition it cannot document.

Paper comes later. According to the château, the first written mention is a 1740 inventory drawn up after the death of Louis Henri de Bourbon, Prince of Condé. It then passed to Queen Marie-Amélie, wife of King Louis Philippe I, and to her son Henri d'Orléans, Duke of Aumale, who left it with his collections to the Institut de France. The record gives 1886 as the date of acquisition.

That bequest is why the Grand Condé diamond sits in Chantilly at all. According to the BBC, the Duke of Aumale left the château to the Institut de France together with thousands of artworks and manuscripts, which together became the Musée Condé collection. The Joconde record lists the owner as a private legal body, which is how the Institut de France is classed, and it bars the stone from being lent.

So the name is older than the evidence. Historic gems often carry stories like this, and a buyer should carry one habit into any purchase: a story is not a provenance.

Why are pink diamonds so rare and so valuable

Natural pink diamonds are rare because almost all of them came from one mine. Rio Tinto's Argyle mine in Western Australia was the world's largest producer of coloured diamonds and supplied most of the world's pinks until it closed in November 2020. Its closure ended the main source of new natural pinks.

Rio Tinto's own final production release describes Argyle as the world's largest producer of coloured diamonds over its life. When the main source of a material stops, the stones already cut become the market, and prices follow.

The top of that market is extreme. Very few people will ever bid there. In April 2017 a 59.60-carat oval Fancy Vivid Pink diamond known as the Pink Star sold at Sotheby's in Hong Kong for $71.2 million, a record for any diamond or jewel at auction at the time. The BBC, citing Sotheby's, still gives it as the highest price ever paid for a pink at auction.

Most pinks a buyer meets in Hatton Garden are nothing like that. They are small, often under a carat, set as accent stones or as a centre in a ring, and their price depends on the strength of the colour as much as the size. Our guide to fancy coloured diamonds explains how colour intensity is described.

What to ask before buying a pink diamond in Hatton Garden

A pink diamond's value rests on what can be proved about it, and the Grand Condé diamond makes the point better than any sales leaflet. These are the questions to put to any jeweller before buying one.

• Is there an independent grading report? Ask for a report from a recognised laboratory such as GIA, and check that the report number matches the one inscribed on the stone, where there is one.
• Is the colour natural? The report should say whether the colour is natural, treated or lab-grown. Each is priced very differently, and none is wrong if it is described honestly.
• How strong is the colour? Pinks are graded by intensity, from faint to vivid, and the grade moves the price as much as the size does.
• Where did it come from? If a seller says a stone is from Argyle, ask which documents support it.
• Can I see it in daylight? Ask to look at the stone by a window as well as under the shop's lights.
• What does the price include? Ask whether the figure covers the setting, the metal and the grading report, or only the loose stone. Get it written on the quote.

Our six tips for buying pink diamonds go into each of these, and our pink diamond engagement ring guide covers settings and metals.

Simplest of all: a good jeweller will put every answer in writing, and in Hatton Garden comparing two or three of them is easy, because they work within a few streets of each other.

If the story has caught your eye, the Grand Condé is at Chantilly until 3 January 2027, and nowhere else. If you are thinking of buying a pink of your own, take the questions above to Hatton Garden and ask for the grading report before you talk about price. As the Grand Condé shows, a famous story and a documented stone are two different things.

Main image: Basile Morin, CC BY-SA 4.0, via Wikimedia Commons.