Geneva in November is where the rarest colored stones of the year come to be judged, and Phillips has just shown its hand. On October 1, 2026, the auction house announced the highlights of The Geneva Jewels Auction: VII, a live sale on November 9 at the Hôtel President Wilson led by a 1.35-carat fancy vivid blue diamond and a 16.40-carat unheated Kashmir sapphire, each estimated at up to CHF 2.87 million.
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At a glance
- The sale: Phillips, The Geneva Jewels Auction: VII, November 9, 2026 at 3pm CET, Hôtel President Wilson, Geneva.
- Top lots: a 1.35-carat fancy vivid blue diamond and a 16.40-carat unheated Kashmir sapphire ring, each estimated at CHF 1.8 million to 2.87 million.
- Royal provenance: a cultured pearl necklace by Hennell, circa 1928, commissioned by Queen Mary, estimated at CHF 125,000 to 180,000.
- Signed jewels: Harry Winston, Van Cleef & Arpels, Boucheron, Lalique and Bucherer.
- Where to see it: a world tour through New York (October 6–8), Singapore, Paris, London and Taipei, then Geneva from November 4.
What is in Phillips’ Geneva Jewels Auction: VII?
The seventh edition of Phillips’ Geneva jewels sale is built around colored stones of documented origin, with a strong thread of royal and historic provenance. Alongside the two headline lots, the house lists an 18.69-carat sugarloaf cabochon Kashmir sapphire in a late 19th-century diamond brooch-pendant (CHF 820,000 to 1.23 million), a 7.96-carat Colombian emerald brooch with no oil (CHF 400,000 to 600,000), and a 4.74-carat unheated Burmese ruby ring (CHF 165,000 to 250,000).
For lovers of white and colored diamonds there is a 10.09-carat D color, Flawless, Type IIa brilliant-cut diamond ring by Bucherer (CHF 290,000 to 450,000), a 9.77-carat faint pinkish brown old mine cut diamond described as Golconda type (CHF 70,000 to 100,000), and a collection of nine colored diamonds ranging from fancy purplish red to fancy vivid yellow (CHF 370,000 to 660,000). Benoît Repellin, Phillips’ Worldwide Head of Jewellery, called it “an exceptional selection of jewels” in the announcement.
How much is the 1.35-carat fancy vivid blue diamond estimated at?
Phillips estimates the brilliant-cut stone at CHF 1.8 million to 2.87 million; Rapaport converts the top figure to about $3.5 million. By our arithmetic, that is roughly CHF 1.33 million to 2.13 million per carat, for a stone smaller than many engagement diamonds. The same budget would buy a 16-carat Kashmir sapphire in the same sale, a telling measure of where vivid blue sits in the hierarchy of color.
Blue diamonds owe their color to traces of boron in the crystal, and gemologists classify them as Type IIb, a group that represents a minute fraction of mined diamonds. The “vivid” grade is the most saturated a laboratory gives, and at the top of the market these stones have set lasting benchmarks: the 14.62-carat Oppenheimer Blue sold at Christie’s Geneva in 2016 for about $57.5 million. The per-carat estimate here shows how that color premium follows a blue diamond all the way down the scale.
Why are Kashmir sapphires so rare and so valuable?
Their story is one of the shortest and most storied in gemology. Sapphires were discovered high in the Padar region of the Kashmir Himalaya around 1881, reportedly exposed by a landslide, and the deposit gave its finest crystals in only a handful of years in the 1880s. Almost every important Kashmir sapphire on the market today was mined well over a century ago.
Connoisseurs prize them for a soft, velvety blue, often described as cornflower, caused by fine inclusions that scatter light and keep the color glowing even in dim rooms. An origin report from a respected laboratory confirming Kashmir, together with “no heat,” is what turns a beautiful sapphire into a legendary one. All three Kashmir lots in this sale are described as unheated, including a 5.62-carat ring from a French noble family (CHF 125,000 to 200,000). Earlier this autumn we followed a Ceylon sapphire that doubled its estimate at Sotheby’s Hong Kong; in our view, Kashmir stones of this size will test how far that appetite for unheated blue now reaches.
A Kashmir sapphire is a century-old stone that has only ever changed hands, never changed its blue.
Which royal and signed jewels are in the sale?
The most evocative lot is not the most expensive. A necklace of 21 cultured pearls, from 5.85 to 13.50 millimeters, with an openwork diamond clasp, was made around 1928 by the London jeweller Hennell and commissioned by Queen Mary, consort of King George V and one of the great royal jewel collectors of the 20th century. Phillips says it was given to Mary Somerset, Duchess of Beaufort, sold in 1986 and has remained in private collections since. It carries an estimate of CHF 125,000 to 180,000 (about $220,000 at the top, per Rapaport).
Other provenance lots include a 19th-century emerald and diamond bracelet presented by Empress Eugénie to Françoise Laurence Staouëli de La Rochelambert (CHF 38,000 to 50,000) and a gold gem-set cross from the collection of the ballet dancer Rudolf Nureyev, estimated at just CHF 1,700 to 2,600. Among signed pieces, Harry Winston’s Colombian emerald earrings of 9.67 and 10.29 carats (CHF 600,000 to 900,000) lead, followed by a Van Cleef & Arpels “Liz” sautoir in amethysts, colored sapphires, coral and diamonds (CHF 200,000 to 300,000) and a Boucheron natural pearl necklace from around 1891 (CHF 70,000 to 100,000).
Where can you see the jewels before the auction?
Phillips is taking the highlights on an international tour: New York at 432 Park Avenue (October 6–8), Singapore at The St. Regis (October 16–17), Paris at Galerie Aveline on the Rue du Faubourg Saint-Honoré (October 17–21), London at 30 Berkeley Square (October 22–24) and Taipei at Hyper Arte (October 23–25), before the full viewing in Geneva from November 4 to 9. For the rest of Geneva’s jewelry week, see our preview of Christie’s Geneva November sale.
For the Collector
- Estimates: published estimates exclude buyer’s premium and fees, so the final cost of a winning bid will be higher. Confirm terms and condition reports directly with Phillips.
- Paperwork is value: for the blue diamond, a laboratory report confirming natural color; for the sapphires, ruby and emeralds, origin and treatment reports. “Kashmir,” “Burma” and “no oil” are what the estimates are paying for.
- Accessible entry points: the Van Cleef & Arpels “Puppy” brooch from around 1966 (CHF 7,000 to 10,000) and the Nureyev cross show that a Geneva jewels sale is not only for seven-figure bidders.
- See it in person: colored stones, especially Kashmir sapphires, are best judged by eye in different lights.
- A word of caution: strong results for rare stones support interest, but past auction prices do not predict future value, and no jewel should be treated as a guaranteed store of value.
For context on how a single legendary colored stone can reset a market, read our story of the Sunrise Ruby.
Frequently asked questions
When is the Phillips Geneva Jewels Auction: VII?
The live sale takes place on November 9, 2026 at 3pm CET at the Hôtel President Wilson in Geneva, with public viewing from November 4.
What is the auction estimate for the blue diamond?
The 1.35-carat fancy vivid blue diamond is estimated at CHF 1.8 million to 2.87 million, or up to about $3.5 million.
Why is an unheated Kashmir sapphire so expensive?
The Kashmir deposit produced its finest stones for only a few years in the 1880s, so supply is fixed and untreated stones with a velvety cornflower blue are exceptionally scarce.
Sources: Phillips press release · Rapaport · NBC News
