PodcastsSep 16, 2026
Episode 9: Remembering Cindy EdelsteinTwo special guests join the podcast to commemorate the 10th anniversary of the designer advocate, mentor, and author’s untimely passing.
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.”
Editors' Picks
Sponsored by
More on Sourcing
The Latest
CollectionsSep 16, 2026
Jessica McCormack, L’Objet Collab on Homewares CollectionMcCormack brings sea-inspired motifs from her “Beaches” collection to L’Objet’s tableware, vanity pieces, and first-ever cutlery set.
CrimeSep 16, 2026
JSA Issues Warning to NJ Jewelers After Rash of Smash and GrabsNine New Jersey jewelers have been victims of smash-and-grab robberies this year, prompting JSA to circulate a list of recommendations.
Brought to you by
Meet Gemology’s Next Generation Microscope: GIA® Gemolite® NXT Professional EditionExperience gemstones with greater precision and comfort than ever before.
IndependentsSep 16, 2026
Bromberg & Co. Names New PresidentMarlin “Brian” Hood, who has been with the store for 20 years, will succeed Ricky Bromberg, who died earlier this month.
Weekly QuizSep 10, 2026
This Week’s QuizTest your jewelry news knowledge by answering these questions.
MajorsSep 16, 2026
Midas Chain Releases ‘House of Midas’ Bridal CatalogThe new bridal catalog features the latest jewelry collections and designs from timeless classics to modern silhouettes.
EditorsSep 15, 2026
2026 Emmys Jewelry: An Either/Or Proposition Stars wore either a necklace or earrings at 78th Primetime Emmy Awards but rarely both, Natalie Francisco notes.
Brought to you by
Your Piece Could Be the One Editors Talk AboutSubmit your pieces for a chance to win in this year's competition.
ColumnistsSep 15, 2026
The Levels Your Website Must Clear Before AI Recommends YouJennifer Shaheen compares this new era of AI-powered SEO to a video game: your website must clear one level before advancing to the next.
IndependentsSep 15, 2026
Armadani Launches Retail Support Program for Holiday SeasonThe program highlights “Made in Italy” fine jewelry with digital merchandising, sales education, and local marketing support.
EditorsSep 15, 2026
Q&A: Signet Jewelers’ Joan Hilson on Diamond Demand, the HolidaysHilson, Signet’s chief operating and financial officer, discussed Q2, resurgent natural diamond demand, and why Blue Nile is a standout.
ColumnistsSep 14, 2026
Sherry Smith: Stop Waiting for December to Save Your ChristmasThe stores that have a great December are the ones that made good decisions in August, September, and October, Sherry Smith writes.
AuctionsSep 14, 2026
22 Carats of ‘Sunshine’ Are Up for AuctionThe 22.09-carat fancy yellow “Pragnell Kimberley Sunshine Diamond” is part of the fall jewelry sale at Heritage Auctions.
IndependentsSep 14, 2026
Greenwich St. Jewelers to Unveil Photography Exhibition“Adornos: Jewelry, Memory & What We Pass Down” honors the jewelry’s importance to New York City’s Latine communities.
CollectionsSep 11, 2026
A Sapphire ‘Stardust’ Ring From Greenwich St. Jewelers The Latine-owned New York jeweler is marking two milestones this year: its 50th anniversary and the 25th anniversary of the 9/11 attacks.
MajorsSep 11, 2026
The Wishing Place by JTV OpensThe jewelry retail broadcast network has sponsored a new space for Make-A-Wish East Tennessee on its campus in Knoxville.
Events & AwardsSep 11, 2026
The Edge Awards Scholarships to 2 Young Jewelry ProfessionalsThe recipients were recognized at the 24 Karat Club of the Southeastern United States’ annual banquet.
MajorsSep 10, 2026
Lagos Founder Steven Lagos Steps Down as CEO Keith Rolfe, CFO and COO of Lagos, is now at the jewelry brand’s helm while Steven takes on the role of executive chairman.
CrimeSep 10, 2026
FBI Offers $50K Reward for ‘Most Wanted’ Fugitive in $1M Jewelry HeistAlberto Perez-Elias is one of four men charged in the armed robbery of a Cape Coral, Florida, jewelry store and remains at large.
AuctionsSep 10, 2026
Massive Matched Pair of Paraíba Tourmalines Head to Sotheby’sThe “Kat Florence Luminas” will be offered together as one lot and could fetch up to $637,000.
SourcingSep 10, 2026
AGTA Announces 4 Newly Elected DirectorsFour directors were elected to the AGTA board and will serve three-year terms beginning in February.
AuctionsSep 10, 2026
Former Sotheby’s, Christie’s Exec Appointed CEO of Julien’s Auctions Ken Citron joins the celebrity memorabilia-focused auction house ahead of its first week-long series of events in Abu Dhabi.
FinancialsSep 09, 2026
Signet Jewelers to ‘Double Down’ on Blue Nile Amid Strong SalesThe jewelry retailer said it sees opportunity at higher price points, particularly in natural diamonds for bridal and fashion.
IndependentsSep 09, 2026
Sarah Leonard Fine Jewelers Closes After Nearly 80 YearsThe Los Angeles-based, family-owned jeweler was founded by Lenny and Sunny Friedman in 1946.
SourcingSep 09, 2026
Fura Gems Notes ‘Remarkable’ Interest in Larger Rubies at Latest SaleThe auction, held in Bangkok, was 96 percent sold by lot, with nearly 411,000 carats of Mozambiquan rubies sold.
MajorsSep 09, 2026
Stuller’s Latest Catalog Includes Its New Demi-Fine CollectionFine Jewelry 2027-2028 has more than 900 new styles, including silver, gold-filled, gold-plated sterling silver, and vermeil jewelry.
Policies & IssuesSep 09, 2026
8 Key Changes the FTC Made to the Jewelry Guides: A Refresher Learn more about the new terms for lab-grown diamonds and composite gemstones, and the major changes in store for precious metals jewelry.
