MajorsDec 30, 2025
Becka Johnson Kibby to Lead Edge Retail AcademyAs part of the leadership transition, Sherry Smith will take on the role of vice president of coaching strategy and development.
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
WatchesDec 30, 2025
Bulova, Stetson Collab on Watches With Western FlairThe new Bulova x Stetson designs highlight two animals often associated with the American West—the bison and the Texas Longhorn.
CollectionsDec 30, 2025
Rahaminov Diamonds Pops Up in FloridaIts residency at Yamron Jewelers will run through May 2026.
Brought to you by
Impacting Tomorrow TodayHow Jewelers of America’s 20 Under 40 are leading to ensure a brighter future for the jewelry industry.
IndependentsDec 29, 2025
In Memoriam: Industry Friends We Lost in 2025From influential executives to innovative designers, we pay tribute to the people we said goodbye to this year.
Weekly QuizDec 23, 2025
This Week’s QuizTest your jewelry news knowledge by answering these questions.
MajorsDec 29, 2025
Tanishq Opens New Stores in Florida, VirginiaThe retailer is expanding into areas with large Indian and South Asian populations.
MajorsDec 29, 2025
Nanis Opens First Flagship Store The Italian brand has opened its first flagship amid the peaks of the Dolomites in Madonna di Campiglio, Italy.
Brought to you by
Roseco Releases New Full-Line CatalogRoseco’s 704-page catalog showcases new lab-grown diamonds, findings, tools & more—available in print or interactive digital editions.
CrimeDec 24, 2025
LA Jewelry District Couple Pleads Guilty to Hiding Millions from IRSThe couple pleaded guilty to concealing at least $127 million in cash transactions at its precious metals businesses.
SurveysDec 24, 2025
Consumer Confidence Falls Again in DecemberConsumers shared concerns about prices, inflation, tariffs, trade, and politics in the survey’s write-in response section.
AuctionsDec 24, 2025
Bonhams to Open New U.S. Flagship in NYCIn February 2026, the auction house will move its headquarters to the former Steinway Hall, a neoclassical landmark on Billionaires’ Row.
Events & AwardsDec 24, 2025
NYC Jewelry, Antique, & Object Show Announces Winter EventThe new show will take place Jan. 23-25, 2026.
SourcingDec 23, 2025
Mining Titan Brian Gilbertson Dies at 82The former BHP Billiton leader and Gemfields chairman is remembered for his influential leadership throughout his 50-year mining career.
Events & AwardsDec 23, 2025
Bulgari Reimagines Costume Designers Guild AwardThe LVMH-owned brand has partnered with the costume design union to revamp its award for 2026.
MajorsDec 23, 2025
Kering to Acquire Stake in Raselli Franco GroupThe luxury titan inked a deal to acquire an initial minority stake in the jewelry manufacturer with a pathway to full ownership by 2032.
MajorsDec 23, 2025
For Future Reference Vintage Enters Bloomingdale’sThe company’s curation of unsigned vintage and estate jewelry debuted at the Bloomingdale’s in Costa Mesa, California.
CrimeDec 22, 2025
Customs Seizes Hundreds of Fake Rolex, Cartier WatchesIn the recent multi-shipment seizure, CBP also found counterfeit Audemars Piguet, Moncler, and Chrome Hearts items.
EditorsDec 22, 2025
How Helzberg Is Reimagining Its StoresHelzberg’s Chief Retail Officer Mitch Maggart shared details about its tests of a new store concept rooted in an elevated luxury experience.
Recorded WebinarsDec 22, 2025
2025 Jewelry Rewind: Looking Back on an Eventful Year Jewelers of America execs and National Jeweler editors discuss tariffs, the sky-high gold price, and the engagement that broke the internet.
MajorsDec 19, 2025
MadaLuxe Group Acquires Ippolita The luxury goods company said founder Ippolita Rostagno will remain at the brand’s helm.
MajorsDec 19, 2025
LVMH Names New Bulgari CEOLaura Burdese, who joined the Italian luxury brand in 2022, will take on the role in July.
EditorsDec 19, 2025
2025 Jewelry Superlatives: A Yearbook-Style Year in Review The National Jeweler editors revisit the most noteworthy industry happenings and design trends from 2025.
AuctionsDec 19, 2025
Jean Schlumberger’s ‘African Cat’ Is Purr-Fection Need a gift for the cat lover who has everything? Look no further than our latest Piece of the Week.
AuctionsDec 18, 2025
Audemars Piguet Reclaims Historic Pocket Watch at AuctionIt purchased the “Grosse Pièce,” an ultra-complicated Audemars Piguet pocket watch from the ‘20s, for a record-breaking price at Sotheby’s.
Lab-GrownDec 18, 2025
Kira Jewels Debuts Custom Lab-Grown Diamond Jewelry ServiceThe lab-grown diamond grower now offers custom engagement and fashion jewelry through its Kira Custom Lab Jewelry service.
EditorsDec 18, 2025
Terry Chandler Looks Back on 40 Years of Opportunity, Change, and FriendsChandler got his start at Michelson Jewelers and has served as DCA president and CEO since 2001. He will retire at the end of the month.
WatchesDec 18, 2025
Bob’s Watches to Open Store in New York’s JFK AirportThe boutique is slated to open this week inside Terminal 8, offering pre-owned Rolex watches and more to international travelers.
