Sotheby’s to Auction 10-Carat Blue Diamond, 1960s Harry Winston Necklace
A private collection of five Paraíba tourmalines also will be up for sale at Sotheby’s High Jewelry auction in New York, scheduled for June 16.

The star of the sale is an unmounted 10.02-carat cut-cornered rectangular modified brilliant fancy intense blue diamond that is estimated to sell for more than $6 million.
It is the third 10-carat-plus fancy intense blue diamond offered at auction since 2008, Sotheby’s said.
A handful of colored diamond rings also are included in the jewelry auction.
A ring featuring a 6.76-carat cushion modified brilliant-cut fancy grayish blue diamond surrounded by pink diamonds is estimated to sell for $1.2 million to $1.8 million, while one set with a 5.02-carat fancy intense pink diamond and two light pink diamonds could fetch $2 million to $3 million.
While blue and pink diamonds are expected to sell for millions, the piece that landed on the cover of the sale’s catalog is a Harry Winston necklace (pictured at the top of the article) set with more than 120 carats of colorless diamonds.
Dating to the 1960s, the necklace features graduated pairs of round diamonds alternating with marquise-shaped diamond clusters, which is unusual for the brand. Harry Winston normally pairs marquise-shaped diamonds with pear cuts—not rounds—in its “Winston Cluster” jewels.
It is estimated to sell for $800,000 to $1.2 million.
The jewelry auction also will feature diamonds from Sotheby’s collaboration with De Beers Group, which celebrates diamonds as cultural icons and works of art.
The sales of the “Jwaneng 28.88,” a round brilliant diamond that sold for $2.7 million at Sotheby’s April high jewelry sale, as well as a pair of 18.38-carat round diamonds that achieved $3.3 million at Sotheby’s Geneva last month, are results of the partnership.
At the upcoming sale, a trio of De Beers diamonds—an 11.33-carat elongated old mine-cut diamond and two pear-shaped diamond rings—will be offered as lots 32, 33, and 34.
The old-mine cut diamond is Type IIa.
Its D color and VVS2 clarity place it among a “very limited category of old mine brilliants where historical form and top-grade gemological quality coincide,” the auction house said.
The “Jwaneng 28.88” and the matching pair referenced above were each cut according to Belgian engineer and diamond cutter Marcel Tolkowsky’s 1919 formula, which is widely regarded as the most ideal proportions for a modern round brilliant diamond.
However, the old-mine cut stone was faceted in “an intentionally non-formulaic manner” that Sotheby’s said reflects the human touch and lends the stone its unique, captivating character.
The diamond is estimated to sell for $600,000 to $800,000.
As for the rings, one has a pre-sale estimate of $25,000 to $35,000, and the other is expected to sell for $30,000 to $50,000.
The proceeds from the rings will be donated to the Peace Parks Foundation, a conservation-focused nonprofit in southern Africa co-founded by the late President Nelson Mandela.
The high jewelry auction also will feature a private collection of Paraíba tourmalines as lots 24-27.
The offering comprises five stones assembled by the scion of an American communications empire founded in the early 1900s, Sotheby’s said.
There is also a 1930s Cartier diamond necklace estimated to sell for $80,000 to $120,000, as well as a 1970s ruby, emerald and diamond sautoir by Van Cleef & Arpels with a pre-sale estimate of $60,000 to $80,000.
In addition, a René Lalique necklace that belonged to a member of the Morgan family, the American banking dynasty that included financier John Pierpont (J.P.) Morgan, will be offered with an estimate of $20,000 to $30,000.
The piece is composed of white diamonds set traditionally in silver-topped gold.
It dates to the late 19th century and is an “unusual and compelling example” of Lalique’s early work, Sotheby’s said, as it differs from the colorful, nature-inspired motifs of the jeweler’s later Art Nouveau style.
To see more of the lots going up for sale at the New York high jewelry auction on June 16, visit the Sotheby’s website.
The Latest

Tara Sinchuri was the owner of Everest Jewels in Fairfield, Ohio, and a father of three. He was found dead in his store on Tuesday.

Bespoke experiences from Buccellati and Verdura are on the retailer’s 2026 “Fantasy Gifts” list.

The number of participants at the fall show was up 12 percent.

A Diamond Is Forever's holiday campaign reimagines natural diamond icons for a new generation celebrating individuality.

The Academy and Grammy award-winning siblings have collaborated with John Hardy on a new jewelry line inspired by their personal style.


Diana Singer shared the stories of two “cursed” diamonds on this month’s podcast, which was inexplicably riddled with technical issues.

The family-owned jeweler has three locations across Missouri and Iowa.

Built on Relationships. Refined by Craft.

The De Beers-owned diamond mine in South Africa is being put on ice as part of a round of previously announced cost-cutting measures.

The collection centers designs with clean geometric lines, chunky sculptural pieces, and recognizable details from the luxury fashion brand.

The miner said it saw particularly strong prices for larger, fine-quality rubies at the sale.

The guard opened fire on a man who was smashing a jewelry display case at La Gran Plaza in Fort Worth last week, police said.

The Texas jeweler added 2,000 square feet to its reimagined showroom, complete with a new design studio and an event space.

Jacob & Co.'s diamond masterpiece is the most expensive Fantasy Bra ever worn on the Victoria’s Secret Fashion Show runway.

The “Atelier” collection was inspired by the tools, rituals, and objects in an artist’s studio as a quiet rebuttal to an automated world.

The pending acquisition is an “exciting opportunity” for wedding vendors to grow their business, said The Knot Worldwide’s CEO.

"The Secret Gems" features eight Thai jewelry brands paired with a team of young craftspeople who create jewelry together to win challenges.

The brand’s “Modern Talisman” capsule collection introduces pendants inspired by the mythology, natural world, and spiritual ethos of Bali.

Independent jewelers from New Mexico to New Jersey answer the question: What has kept your store in business for 100 years?

The NRF is expecting holiday sales to increase this year, but consumers and retailers alike are facing Grinch-like headwinds.

Our Piece of the Week gathers the planets, represented by a variety of colored gemstones, in a pair of 14-karat yellow gold earrings.

The New York-based jeweler is moving its Amherst flagship store to a larger location in nearby Snyder.

Chen, who worked at Cartier and Tiffany & Co., will lead retail sales and operations for the luxury jeweler’s 11 U.S. stores.

For 40 years, sisters Amy and Elise Greenberg have helmed their 126-year-old family business, leading with appreciation and integrity.

It’s a term Smith coined and felt compelled to share following a bad experience with an aborted flight and an unfeeling flight attendant.

Movado teamed up with the New York-based fine jewelry designer on a new collection of Movado Museum Velura watches.

The two companies are reportedly in talks to join the Global Diamond Consortium, led by former De Beers CEO Gareth Penny, as per Bloomberg.























