The Devonshire Cartier opal tiara has witnessed two royal coronations. Now, the Art Deco jewel designed to transform into a necklace and a series of brooches is set to headline Sotheby’s Royal & Noble Jewels auction in Geneva on November 11, 2026. Its estimate is CHF 780,000 to CHF 1.1 million (approximately US$945,000 to US$1.3 million).
Cartier created the piece around 1937 for Mary Cavendish, then Marchioness of Hartington, who would later become Duchess of Devonshire. Sotheby’s believes it was commissioned for the coronation of King George VI. According to family history, the black opals were given to the Marquess and Marchioness during a government tour of Australia and New Zealand in 1936–37, then provided to Cartier by the client.
The Devonshire Cartier opal tiara, made around 1937 for Mary Cavendish, Duchess of Devonshire, is among the highlights of Sotheby’s Royal & Noble Jewels sale in Geneva. Worn at Queen Elizabeth II’s 1953 coronation, the convertible Art Deco jewel is estimated at CHF 780,000 to CHF 1.1 million (approximately US$945,000 to US$1.3 million). The auction is scheduled for November 11, 2026, at 5 p.m. CET.
Its most celebrated appearance came in 1953. As Mistress of the Robes to Queen Elizabeth II, the Dowager Duchess of Devonshire walked behind the monarch and her train-bearers during the coronation procession. She wore the opal necklace alongside the Devonshire palmette tiara. Sotheby’s describes it as one of the ceremony’s most visible jewels, after the Queen’s own. The jewel’s design allows it to be worn in several ways. Five removable brooches each feature an oval black opal surrounded by old mine-cut, old European-cut, and single-cut diamonds, with baguette diamonds and a pear-shaped diamond at the front. A tiara fitting and a devant-de-corsage fitting for the three central brooches are included, along with a fitted Cartier case.
The piece appeared in the Victoria and Albert Museum’s Cartier exhibition in London in 2025. More recently, director Emerald Fennell wore the necklace to the London premiere of her Wuthering Heights adaptation on February 5, 2026.
Other lots bring their own royal histories. A Mellerio dits Meller diamond tiara, created for the 1862 London International Exhibition, was presented to Marie Isabelle of Orléans as a wedding gift in 1864, when she married the Count of Paris. Its Greek key design can also be worn as a necklace. The estimate is CHF 300,000 to CHF 500,000 (approximately US$365,000 to US$605,000).
Marie Isabelle’s eldest daughter, Amélie of Orléans, the last Queen of Portugal, is linked to an antique emerald and diamond bangle from the 1880s. Its detachable centre holds a 27.38 carat Colombian cabochon emerald and is estimated at CHF 70,000 to CHF 100,000 (approximately US$85,000 to US$120,000).
Among the other notable pieces is a toi et moi ring pairing a 7.83-carat Kashmir sapphire with a 6.77-carat Colombian emerald. Sotheby’s associates the ring with Catherine Walston, who inspired Graham Greene’s The End of the Affair. It carries an estimate of CHF 350,000 to CHF 500,000 (approximately US$425,000 to US$605,000). A Bucherer necklace centred on a 43.07-carat Ceylon sapphire is estimated at CHF 320,000 to CHF 480,000 (approximately US$390,000 to US$580,000).
For this sale, provenance is central to the appeal. Sotheby’s presents its November Geneva jewellery auction as an annual tradition, noting that each of the past three editions achieved white-glove status. The Devonshire jewel’s journey from a coronation procession to a recent film premiere makes it a particularly compelling lot to watch. Highlights were scheduled to be shown at Sotheby’s Zurich, Rämistrasse 3, through October 23, and at The Gallery Ital Auto Ferrari in Singapore from October 22 to 25. The full sale exhibition is scheduled at the Mandarin Oriental, Geneva, from November 6 to 10, daily from 10 a.m. to 6 p.m. The live auction is set for November 11 at 5 p.m. CET.
