FinancialsMar 10, 2026
Signet Jewelers’ Q4 Sales Fall Flat The jewelry giant released preliminary results for the fourth quarter and full year on Monday, with final results slated to come next week.
SourcingApr 29, 2019
Botswana’s Karowe Mine Yields Another Huge Stone
It weighs 1,758 carats and is described as being “near-gem of variable quality.”
This 1,758-carat stone just found at the Karowe mine in Botswana weighs close to 352 grams and measures 83 mm x 62 mm x 46 mm. It is approximately as big as a “good-sized pear,” miner Lucara Diamond Corp. said.
Letlhakane, Botswana—Lucara Diamond Corp. announced last Thursday that it found a 1,758-carat piece of rough at the same mine where it recovered the 1,109-carat Lesedi La Rona.
Discovered over Easter weekend, the huge stone is still being analyzed, but Lucara described it as being “near-gem of variable quality,” meaning it is an industrial diamond with sections that could produce gem-quality stones.
The 1,758-carater is one of largest rough diamonds recovered in recent history, and the second 1,000-carat-plus stone recovered from Karowe since 2015.
The largest known gem-quality diamond in history is the Cullinan, which was found in South Africa in 1905.
There has been a larger stone recovered than the Cullinan—the 3,167-carat carbonado diamond dubbed the “Carbonado do Sergio” discovered in Brazil in 1895. Carbonado diamonds are industrial-quality stones that are opaque and believed to be found only in Brazil and the Central African Republic, Stephen E. Haggerty, a research professor at Florida International University in Miami, wrote in the summer 2017 issue of GIA’s Gems & Gemology.
Discovered over Easter weekend, the huge stone is still being analyzed, but Lucara described it as being “near-gem of variable quality,” meaning it is an industrial diamond with sections that could produce gem-quality stones.
The 1,758-carater is one of largest rough diamonds recovered in recent history, and the second 1,000-carat-plus stone recovered from Karowe since 2015.
The largest known gem-quality diamond in history is the Cullinan, which was found in South Africa in 1905.
There has been a larger stone recovered than the Cullinan—the 3,167-carat carbonado diamond dubbed the “Carbonado do Sergio” discovered in Brazil in 1895. Carbonado diamonds are industrial-quality stones that are opaque and believed to be found only in Brazil and the Central African Republic, Stephen E. Haggerty, a research professor at Florida International University in Miami, wrote in the summer 2017 issue of GIA’s Gems & Gemology.
This photo provided by Lucara Diamond Corp. shows a bit of light coming through the back of the 1,758-carat chunk of rough found at Karowe mine over Easter weekend.
Lucara recovered the huge stone using XRT (X-ray transmission) technology from Tomra Sorting Solutions, which designs and manufactures sorting equipment for the mining, food and recycling industries.
In the past, many large rough diamonds were crushed during recovery because De Beers, the main diamond miner at that time, did not have the technology to detect them and, to an extent, did not care, Gemological Institute of America Senior Analyst Russ Shor wrote in a 2016 research article.
Making money in diamond mining was about speed, he wrote, with the per-carat price differential between large (above 10 carats) and small diamonds not enough to make it worth De Beers’ while to retool its processing.
(De Beers actually was the company that discovered the kimberlite pipe at Karowe in 1969 but never commercially mined the deposit. It sold its final stake in the site to Lucara in 2010.)
RELATED CONTENT: Graff Cut This 302-Carat Diamond from Lesedi La Rona
Today, large diamonds fetch huge sums on the global market so miners are putting time and money into technology that spares them.
Tomra’s XRT is sensor-based bulk sorting that can pick out the diamonds even if they are coated, low-luminescent or Type II, the company says.
Lucara implemented XRT at Karowe in 2015 and, since that time, it said it has recovered 12 diamonds weighing 300 carats or more. Half of those dozen diamonds have been gem quality and sold for a total of more than $158 million.
This includes the 1,109-carat Lesedi La Rona, which turned up in fall 2015.
Lucara expects to keep finding large, high-quality diamonds at Karowe, noting: “Each deposit has a characteristic size distribution of diamonds … The vast majority of diamond mines have ‘fine’ distributions and host [very] few large/coarse diamonds, regardless of grade. The Karowe mine has a very coarse distribution of large diamonds, up to 5 times the world average.”
More on Sourcing
The Latest
MajorsMar 10, 2026
Saks Global to Close 15 More StoresThe retailer also gave an update on its vendor partnerships.
TrendsMar 10, 2026
Messika Names Julianne Moore as AmbassadorThe award-winning actress is the “epitome of modern allure,” the brand said.
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.
CollectionsMar 10, 2026
Gemstones ‘Bloom’ in Sorellina’s New CollectionThe “Bloom” collection draws from the flower power movement of the 1960s and ‘70s with inlay pendants offered in eight colorways.
Weekly QuizMar 05, 2026
This Week’s QuizTest your jewelry news knowledge by answering these questions.
Events & AwardsMar 10, 2026
Diamond-Studded Painting Shines at RJO Foundation AuctionThe unique piece was one of the custom works offered at the foundation's recent silent art auction, which garnered nearly $15,000 in total.
TrendsMar 09, 2026
Jake Gyllenhaal Is Bulgari’s Latest AmbassadorBulgari named Gyllenhaal as its brand ambassador for his embodiment of artistic depth, intellectual curiosity, and warmth.
Brought to you by
DCA Enters a New Chapter in Jewelry EducationWith refreshed branding, a new website, updated courses, and a pathway for growth, DCA is dedicated to supporting retail staff development.
Events & AwardsMar 09, 2026
TJS Announces 2026 Scholarship WinnersAwards were given to four students, one apprentice, and an emerging jeweler.
AuctionsMar 09, 2026
Joanna Carson’s Jewels Lead White-Glove SaleThe top jewelry lot of the late model’s estate sale, hosted by John Moran Auctioneers, was an Oscar Heyman & Brothers for Cartier necklace.
GradingMar 06, 2026
Tom Moses Leaving GIA After Nearly 50 YearsMoses, who started at GIA’s Santa Monica lab in 1976, will leave the Gemological Institute of America in May.
Lab-GrownMar 06, 2026
Charles & Colvard Files for Bankruptcy, Citing Price PressuresIncreased competition, falling lab-grown diamond and moissanite prices, and the rising cost of gold took a toll on the moissanite maker.
CollectionsMar 06, 2026
Zome’s ‘Solara’ Earrings Embody Celestial BeautyThe earrings, our Piece of the Week, feature pink tourmalines as planets orbiting around an aquamarine center set in 18-karat rose gold.
MajorsMar 06, 2026
Pomellato’s 2026 IWD Campaign Spotlights Economic Abuse“The Price of Freedom” campaign video for International Women’s Day confronts the quiet violence of financial control.
Policies & IssuesMar 05, 2026
Tariffs to Increase to 15% This Week, Treasury Secretary Says Also, a federal judge has ordered that companies that paid tariffs implemented under the IEEPA are entitled to refunds.
CollectionsMar 05, 2026
Common Era Honors ‘Difficult Women’ in CollectionThe ever-growing collection, which just expanded with the addition of Olga of Kyiv, features cameos of 12 women from history.
TrendsMar 05, 2026
Engagement Ring Trends 2026: What’s In, and WhyWe asked a jewelry historian, designer, bridal director, and wedding expert what’s trending in engagement rings. Here’s what they said.
Events & AwardsMar 05, 2026
AGS Announces Conclave 2026 Speaker LineupThe annual event will be held in Orlando, Florida, from Sept. 14-17.
TrendsMar 05, 2026
Caitríona Balfe Fronts Only Natural Diamonds CoverThe “Outlander” star modeled for the digital cover of the magazine’s spring issue, which features a story on her relationship with jewelry.
MajorsMar 05, 2026
Registration Opens for CIBJO Centenary CongressThis year’s annual congress, which will mark the confederation’s 100th anniversary, will take place this fall in Italy.
MajorsMar 04, 2026
Michael M Opens First StoreBeverly Hills was chosen as the location for the brand’s first store, designed as a “private residence for modern monarchs.”
Policies & IssuesMar 04, 2026
Luxury Brands Temporarily Shutter Middle East StoresKering, Apple, and other retailers have reportedly temporarily closed stores in the Middle East region in light of the recent conflicts.
EditorsMar 04, 2026
Q&A: Brilliant Earth’s CEO on the New Beverly Hills StoreBeth Gerstein discusses the vibe of the new store, what customers want when fine jewelry shopping today, and the details of “Date Night.”
Events & AwardsMar 04, 2026
JIS Miami Spring Show to Feature New Gifts Pavilion, Pop-Up Trends TalksNearly half of buyers are prioritizing silver and fashion collections this season, organizers said.
TrendsMar 04, 2026
Spinelli Kilcollin Rides Free In Year of the Horse CampaignThe “Live Now. Polish Later.” campaign features equestrians wearing the brand’s jewels while galloping across the icy plains of Kazakhstan.
MajorsMar 04, 2026
LeachGarner Names New Brand DirectorThe precious metals provider has promoted Jennifer Ashworth to the role.
Events & AwardsMar 03, 2026
Johnny Nelson Wins David Yurman Gem Awards GrantNelson will be honored as the inaugural grant winner at the Gem Awards gala on March 13.
