‘Rarest of the Rare’ Blue Diamond Expected to Top $48M at Auction
The 15.10-carat fancy vivid blue, mined by Petra last spring and purchased by De Beers and Diacore, heads to Sotheby’s in April.

Sotheby’s announced Wednesday it will offer the 15-carat fancy vivid “De Beers Cullinan Blue Diamond” in a single-lot sale this spring.
The diamond is estimated to sell for more than $48 million, or $3.2 million per carat.
Mining company Petra Diamonds uncovered the original rough, weighing 39.34 carats, at the Cullinan mine in April 2021.
De Beers Group and manufacturer Diacore International, a De Beers sightholder and master diamond cutter, purchased the stone for $40.2 million last July.
Since then, the companies have been analyzing, cutting and polishing the stone to bring the diamond that’s been dubbed the De Beers Cullinan Blue to life.

What emerged is an internally flawless 15.10-carat step-cut fancy vivid blue diamond Sotheby’s is calling the largest vivid blue diamond ever to appear at auction.
The GIA Monograph Report on the stone states: “Achieving a fancy vivid color grade in a step cut or emerald cut adds to the rarity, since most other fancy shapes intensify the body color more efficiently in the face-up position than step cuts. To achieve a fancy vivid grade with a step cut or emerald cut, the inherent bodycolor has to be stronger than virtually every other fancy shape.”
Sotheby’s will offer the diamond in a live single-lot auction in late April—tentatively April 27—anchoring Sotheby’s Hong Kong Luxury Week.
Prior to that, it will be showcased in a worldwide tour, starting in New York before traveling to London, Dubai, Shanghai, Beijing, Shenzhen, and Taipei.

“Blue diamonds of any kind are rare on the market, but this is the rarest of the rare; nothing of remotely similar caliber has appeared at auction in recent years. Hundreds of millions of years in the making, this extraordinary blue diamond is surely one of nature’s finest creations,” said Patti Wong, chairman of Sotheby’s Asia.
“Now brought to dazzling life by the hand of one of the world’s most skillful cutters, it is the ultimate masterpiece—as rare and desirable as the very greatest works of art. At a time of unprecedented demand for the finest, world-class, colored diamonds, we are incredibly excited to bring to the market what is sure to become one of the most celebrated gems in the world.”
According to Sotheby’s, only five blue diamonds weighing more than 10 carats have gone to auction before, with none exceeding 15 carats.
The world auction record for highest price per carat belongs to “The Blue Moon of Josephine,” a 12.03-carat internally flawless cushion-shaped fancy vivid blue diamond, which sold for $48.5 million, or about $4 million per carat, in November 2015.
The “Oppenheimer Blue,” a 14.62-carat fancy vivid blue step-cut diamond, sold for $57.5 million in May 2016, setting the record for the most expensive jewel sold at auction.
The 59.60-carat “Pink Star” diamond later eclipsed the Oppenheimer Blue, selling for $71.2 million in April 2017. It remains the most expensive jewel ever sold at auction.
The Latest

The Vault’s Katherine Jetter is accusing the retailer of using info she shared for a potential partnership to move into Nantucket.

Agents seized 2,193 pieces, a mix of counterfeit Cartier “Love” and “Juste Un Clou” bracelets, and Van Cleef & Arpels’ “Alhambra” design.

The designer brought her children’s book, “The Big Splash Circus,” to life through a collection of playful fine jewelry characters.

The Seymour & Evelyn Holtzman Bench Scholarship from Jewelers of America returns for a second year.

The trade association has chosen the recipients of the funding initiative it formed to foster the growth and sustainability of the industry.


The organization has also announced this year’s slate of judges.

Associate Editor Natalie Francisco shares 20 additional pieces that stood out to her at the Couture show.

The countdown is on for the JCK Las Vegas Show and JA is pulling out all the stops.

Lori Tucker started at Williams Jewelers when she was 18 years old.

The “Marvel | Citizen Zenshin” watch is crafted in Super Titanium and has subtle nods to all four “Fantastic Four” superheroes on the dial.

The “XO Tacori” collection was designed to blend luxury and accessible pricing.

Pritesh Patel, the lab’s chief operating officer, will take over as president and CEO of GIA.

National Jeweler and Jewelers of America discuss the standout jewelry trends and biggest news to emerge from the shows this year.

Signatories to the “Luanda Accord” committed to allocating 1 percent of annual diamond revenue to the Natural Diamond Council.

The winning designs captured the “Radiance” theme.

Nominations in the categories of Jewelry Design, Media Excellence, and Retail Innovation will be accepted through July 30.

The singer’s ring ticks off many bridal trends, with a thick band, half-bezel setting, and solitaire diamond.

The bracelet references vintage high jewelry and snake symbolism as a playful piece where a python’s head becomes a working belt buckle.

The heist happened in Lebec, California, in 2022 when a Brinks truck was transporting goods from one show in California to another.

The Starboard Cruises SVP discusses who is shopping for jewelry on ships, how much they’re spending, and why brands should get on board.

To mark the milestone, the brand is introducing new non-bridal fine jewelry designs for the first time in two decades.

The gemstone is the third most valuable ruby to come out of the Montepuez mine, Gemfields said.

Founder and longtime CEO Ben Smithee will stay with the agency, transitioning into the role of founding partner and strategic advisor.

Associate Editor Natalie Francisco shares 20 of her favorite pieces from the jewelry collections that debuted at Couture.

If you want to attract good salespeople and generate a stream of “sleeping money” for your jewelry store, then you are going to have to pay.

The top lot was a colorless Graff diamond, followed by a Burmese ruby necklace by Marcus & Co.

Gizzi, who has been in the industry since 2001, is now Jewelers of America’s senior vice president of corporate affairs.