TechnologyJun 27, 2025
Gemist Raises $6M in Funding to Scale Jewelry Tech PlatformThe company is focused on modernizing the custom jewelry buying experience with e-commerce tools like product visualization and 3D styling.
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
IndependentsJun 27, 2025
David Webb Announces New Hires, PromotionsFollowing its recent acquisition, the storied brand has updated its leadership team and regional managers.
Events & AwardsJun 27, 2025
AGS, GIA Announce Beatrice Shipley Scholarship Winner AGS also named the recipient of its “Women in Leadership” scholarship.
Brought to you by
Investing in the Next Generation of Bench JewelersThe Seymour & Evelyn Holtzman Bench Scholarship from Jewelers of America returns for a second year.
CollectionsJun 27, 2025
Piece of the Week: Buddha Mama’s ‘Monstera’ Wrap RingThe 20-karat yellow gold and diamond wrap ring is modeled after the Monstera plants in the garden of the brand’s Miami villa.
Weekly QuizJun 26, 2025
This Week’s QuizTest your jewelry news knowledge by answering these questions.
MajorsJun 26, 2025
Why Rocksbox Is Opening Stores As Signet Jewelers DownsizesRocksbox President Allison Vigil shared the retailer’s expansion plans, and her thoughts on opening stores in malls.
IndependentsJun 26, 2025
Penny Ruston Dies at 80 The creator of the WJA Chicago chapter is remembered as a champion for women in the jewelry industry and a loving grandmother.
Brought to you by
Jewelers of America is Headed to Las Vegas for JCK 2025The countdown is on for the JCK Las Vegas Show and JA is pulling out all the stops.
SurveysJun 26, 2025
After Recovering in May, Consumer Confidence Dips in June The decline was consistent across age groups and almost all income groups, with tariffs and inflation still top of mind.
CollectionsJun 26, 2025
Jam Out With Sorellina’s Jimi Hendrix-Inspired JewelsThe “Playlist: Electric Dreams” collection brings lyrics from the musician’s song, “Little Wing,” to life through fine jewelry.
Events & AwardsJun 26, 2025
The Jewelry Symposium Is Looking for Speakers for 2026 EventThe event is set for May 16-19 in Detroit, Michigan.
IndependentsJun 25, 2025
Marissa Collections Opens in Nantucket as Legal Fight ContinuesThe Vault’s Katherine Jetter is accusing the retailer of using info she shared for a potential partnership to move into Nantucket.
CrimeJun 25, 2025
Customs Nabs Another Big Shipment of Fake Cartier, Van Cleef JewelryAgents seized 2,193 pieces, a mix of counterfeit Cartier “Love” and “Juste Un Clou” bracelets, and Van Cleef & Arpels’ “Alhambra” design.
CollectionsJun 25, 2025
Splash into Karina Choudhrie’s Collection of Underwater Circus PerformersThe designer brought her children’s book, “The Big Splash Circus,” to life through a collection of playful fine jewelry characters.
Events & AwardsJun 25, 2025
JA Announces Impact Initiative Fund RecipientsThe trade association has chosen the recipients of the funding initiative it formed to foster the growth and sustainability of the industry.
EditorsJun 24, 2025
The Best New Jewelry from Couture 2025, Part 2Associate Editor Natalie Francisco shares 20 additional pieces that stood out to her at the Couture show.
IndependentsJun 24, 2025
Colorado Bench Jeweler Celebrates 50 Years With Local RetailerLori Tucker started at Williams Jewelers when she was 18 years old.
WatchesJun 24, 2025
Citizen’s New ‘Fantastic Four’ Watch Is Literally Super The “Marvel | Citizen Zenshin” watch is crafted in Super Titanium and has subtle nods to all four “Fantastic Four” superheroes on the dial.
MajorsJun 24, 2025
Tacori, QVC to Launch Exclusive Lab-Grown Diamond Jewelry CollectionThe “XO Tacori” collection was designed to blend luxury and accessible pricing.
GradingJun 23, 2025
GIA Names New President and CEO Pritesh Patel, the lab’s chief operating officer, will take over as president and CEO of GIA.
Recorded WebinarsJun 23, 2025
Watch: Top Trends at Couture, JCK Las Vegas 2025National Jeweler and Jewelers of America discuss the standout jewelry trends and biggest news to emerge from the shows this year.
Events & AwardsJun 23, 2025
Jose Hess Design Awards Celebrate 6 Jewelry DesignersThe winning designs captured the “Radiance” theme.
Events & AwardsJun 23, 2025
Gem Awards Now Accepting Nominations for 2026Nominations in the categories of Jewelry Design, Media Excellence, and Retail Innovation will be accepted through July 30.
TrendsJun 20, 2025
Dua Lipa Stays On-Trend With Chunky Engagement RingThe singer’s ring ticks off many bridal trends, with a thick band, half-bezel setting, and solitaire diamond.
TrendsJun 20, 2025
Piece of the Week: Yvonne Léon’s ‘Python Gold’ BraceletThe bracelet references vintage high jewelry and snake symbolism as a playful piece where a python’s head becomes a working belt buckle.
CrimeJun 18, 2025
7 Men Indicted in $100M Brinks Jewelry HeistThe heist happened in Lebec, California, in 2022 when a Brinks truck was transporting goods from one show in California to another.
AuctionsJun 18, 2025
Historic ‘Marie-Thérèse Pink’ Diamond Fetches $14M at Christie’sThe 10-carat fancy purple-pink diamond with potential links to Marie Antoinette headlined the white-glove jewelry auction this week.
