Sourcing

De Beers, Diacore Buy Blues From the Cullinan Mine

SourcingNov 30, 2020

De Beers, Diacore Buy Blues From the Cullinan Mine

The two companies paid a little over $40 million for the five diamonds, which range in size from 10 to 26 carats.

20201021_Blue_Diamonds_Cullinan.jpg
The five blue diamonds recovered from the Cullinan Mine over the course of the same week in September are, from left to right, 9.61, 11.42, 17.57, 21.25, and 25.75 carats. (Photo courtesy of Petra Diamonds)

London—De Beers Group and Diacore are partnering to buy the five blue diamonds recovered from South Africa’s Cullinan Mine in the same week earlier this year.

De Beers and the diamond manufacturer are paying $40.36 million, split equally between the two companies, for the collection, which totals 85.62 carats and ranges in size from about 10 to 26 carats.

Two natural color diamond experts, Joseph Namdar of Namdar Inc. and Eden Rachminov, said they cannot comment on the purchase price until the diamonds are polished and graded.

“I can tell you with absolute certainty, however, that the buyers are counting on the diamonds being graded as fancy vivid blue,” Namdar said. “Even if they are all graded intense blue, I don’t believe they (De Beers and Diacore) will cover their investment.”

Rachminov, chairman of the board of the Fancy Color Research Foundation, which collects and analyzes wholesale and retail data on fancy color diamonds, called the purchase of the five blue diamonds a “smart move.”

“Generally speaking, any rare fancy color diamond is considered to be a safe purchase these days as the supply diminishes year after year,” he said.

“We also see that fancy color diamond producing mines are slowly closing, such as the Argyle mine, and other mines’ futures, such as Petra (Cullinan) in South Africa and Dominion (Ekati) in Canada, are not clear.”

The diamonds (which can be seen below in the slideshow, in ascending order of size) are: 9.61, 11.42, 17.57, 21.25, and 25.75 carats.

De Beers and Diacore said in the news release on the purchase of the diamonds they will select
“expert craftsmen” to study and cut the diamonds.


Petra announced it was selling the five blue diamonds via tender about a month ago, immediately after the financially troubled miner handed itself over to lenders in a debt-for-equity restructuring deal.

The diamond miner is also dealing with allegations that security employees and contractors at the Williamson mine in Tanzania beat and shot at artisanal miners who trespassed on the site, killing at least seven of them. Petra owns a 75 percent stake in the mine; the government of Tanzania owns the other 25 percent.

Leigh Day, the same U.K. law firm that sued Gemfields over human rights abuses at its ruby mine in Mozambique, has filed a claim against Petra in the High Court in London on behalf of 35 Tanzanians who
live near the mine and claim they, or their family members, were abused by the mine’s security forces.
Michelle Graffis the editor-in-chief at National Jeweler, directing the publication’s coverage both online and in print.

The Latest

Macy’s New York City Herald Square flagship
FinancialsMar 20, 2026
Macy’s Turnaround Plans Shows Promise, Boosted by Bloomingdale’s

Plus, why Saks Global’s bankruptcy may have given Bloomingdale’s an edge.

Jwaneng Diamond
AuctionsMar 20, 2026
Sotheby's, De Beers Unveil ‘Jwaneng 28.88’ Diamond

The flawless, Type IIa stone is estimated to achieve up to $2.8 million at the auction house’s high jewelry sale in April.

Tiffany & Co.’s Three Jean Schlumberger for Tiffany & Co. Archives Brooches
TrendsMar 20, 2026
‘Frankenstein’ Costume Designer Is Bejeweled In Brooches for Oscars Win

Costume designer Kate Hawley wore three archival Tiffany & Co. brooches, our Pieces of the Week, while accepting her first Oscar.

GIA iD100®
Brought to you by
Protect Your Customers and Your Business

You deserve to know what you are selling–to protect your customers as well as your business and your reputation.

Women wearing Zales jewelry
FinancialsMar 19, 2026
Signet Jewelers to Close 100 Stores, Shutter James Allen Banner

The jewelry retailer announced changes to its store network and brand portfolio during its fourth-quarter earnings call.

Weekly QuizMar 19, 2026
This Week’s Quiz
Test your jewelry news knowledge by answering these questions.
Take the Quiz
Hand holding shopping bags
SurveysMar 19, 2026
NRF Forecasts 4% Retail Sales Growth in 2026

From a weaker labor market to inflation, NRF Chief Economist Mark Mathews gave insight on what retailers can expect this year.

26.36 carat round brilliant cut white diamond
AuctionsMar 19, 2026
26-Carat Diamond Tops $1M at Auction

The historic stone, which sold at Elmwood’s in London, is the largest white diamond to be offered on the U.K. market in more than a decade.

TopImageCrop.jpg
Brought to you by
Is This You? Every Jeweler Has This Problem; We Have the Solution.

Every jeweler faces the same challenge: helping customers protect what they love. Here’s the solution designed for today’s jewelry business.

JCK Rocks Nelly Graphic
Events & AwardsMar 19, 2026
JCK Rocks To Ride With Nelly

Three-time Grammy award-winning artist Nelly is set to perform at the annual event at Tao Beach in Las Vegas on May 31.

Lady Wardington and diamond-clip brooch
AuctionsMar 18, 2026
Collection of the ‘Severely Beautiful’ Lady Wardington Fetches $161K

The model and fashion editor’s gold evening bags were the top lots at the London sale, going for more than $25,000 each.

My Next Question Episode 3 guest Johnny Nelson
PodcastsMar 18, 2026
Episode 3: An Interview With Jewelry Designer Johnny Nelson

Fresh off winning the David Yurman Gem Awards Grant, Nelson discusses the ring that launched his career and his plans for the future.

Stuller The Basics of Jewelry
MajorsMar 18, 2026
Stuller Releases New Edition of Jewelry Education Book

“The Basics of Jewelry” has been updated to include modern topics and visuals.

Mark and Candy Udell on stage at the 2026 Gem Awards
Events & AwardsMar 17, 2026
The Best Moments From the 2026 Gem Awards

Held just before the Oscars, the jewelry industry’s big awards show had its share of standout jewelry, gowns, and acceptance speeches.

Natalie Portman in Tiffany & Co. Jewelry
TrendsMar 17, 2026
Natalie Portman Is Tiffany & Co.’s New Ambassador

The Academy Award-winning actress stars in Tiffany & Co.’s latest commercial, which debuted Sunday night during the Oscars.

Jean-Marc Duplaix
MajorsMar 17, 2026
Kering Establishes Jewelry Division, Appoints CEO

The organizational change follows Kering’s promise of a transformation after declining sales in 2025.

Anne Hathaway and Rose Byrne
EditorsMar 16, 2026
2026 Oscars Jewelry: One Necklace After Another

Natalie Francisco rounds up the top Oscars jewels, including Rose Byrne’s Taffin necklace with a more than 20-carat yellow-brown diamond.

Tag Heuer CEO Béatrice Goasglas
WatchesMar 16, 2026
TAG Heuer Has a New CEO

Béatrice Goasglas has been with TAG Heuer since 2018. She is the first woman to head the 166-year-old, LVMH-owned watch brand.

Ben Bridge Jeweler Honolulu boutique
IndependentsMar 16, 2026
Ben Bridge Debuts New Honolulu Boutique

The store features the first in-store build for the jeweler’s in-house “Bella Ponte” bridal brand.

Bonhams fine jewelry Paris
AuctionsMar 16, 2026
Bonhams Paris To Offer Antique, Signed Jewels

The live fine jewelry auction will take place later this week, showcasing antique pieces, rare gemstones, and signed jewels.

Silvia Furmanovich Horse Mane Earrings, Cece Jewellery Underworld Triptych Necklace, Almasika Invictus Flower Brooch
CollectionsMar 13, 2026
A Trio of Jewels from the 3 Gem Award Nominees for Jewelry Design

Our Pieces of the Week honor the 2026 nominees for the Gem Award for Jewelry Design, Silvia Furmanovich, Cece Fein-Hughes, and Catherine Sarr.

Vera Wang
WatchesMar 13, 2026
Citizen, Vera Wang to Launch Watch Collection

The 24-piece watch collection is set to debut in spring 2027.

Andrea Pooler
SourcingMar 13, 2026
Andrea Pooler Joins Third-Generation Diamond Company as COO

Pooler, who has more than 25 years’ experience in jewelry, is now chief operating officer of Modani Jewels, Soham Diamonds, and SNJ Creations.

24 Karat Club banquet
MajorsMar 13, 2026
24 Karat Club of New York’s Banquet to Return to Waldorf Astoria

The reopening of the Waldorf Astoria means a homecoming for the industry group’s annual event, which will take place Saturday.

Zoë Kravitz in Jessica McCormack’s Planetary Necklace
CollectionsMar 12, 2026
Jessica McCormack Sends Gold, Gemstones Into ‘Orbit’

McCormack looked to the 19th century’s “golden age” of astronomy when designing her new celestial-themed collection.

Johnny Nelson Wins David Yurman Gem Award Grant Graphic
Events & AwardsMar 12, 2026
Johnny Nelson Wins David Yurman Gem Awards Grant

Nelson will be honored as the inaugural grant winner at the Gem Awards gala on Friday.

David Berdugo
TechnologyMar 12, 2026
Caratwise Launches, Names Former Signet Exec CEO

The new smart design software allows jewelers to configure, price, and confirm a custom engagement ring in real time for in-store customers.

Woman working at bruting machine, seal at new Grandview Klein factory in South Africa
SourcingMar 12, 2026
Grandview Klein Opens New Factory in South Africa

The 10,000-square-foot diamond manufacturing facility officially opened in late February and employs 50 people.

×

This site uses cookies to give you the best online experience. By continuing to use & browse this site, we assume you agree to our Privacy Policy