Sourcing

Botswana’s Karowe Mine Yields Another Huge Stone

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.”

20190429_1758_header.jpg
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.

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.
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.”
Michelle Graffis the editor-in-chief at National Jeweler, directing the publication’s coverage both online and in print.

The Latest

F.P. Journe FFC prototype
AuctionsDec 10, 2025
Francis Ford Coppola’s Watch Sells for $10.8M

The filmmaker’s personal F.P. Journe “FFC” prototype was the star of Phillips’ recent record-setting watch auction in New York.

Rolex Miami store
WatchesDec 10, 2025
There’s A New Rolex Boutique in Miami

The new location in the Design District pays homage to Miami’s Art Deco heritage and its connection to the ocean.

Stock image of consumers shopping in the winter
SurveysDec 10, 2025
Consumer Confidence Drops in November

Inflations, tariffs, and politics—including the government shutdown—were among consumers’ top concerns last month.

Recipients Collage 2025 - NJ (1872 x 1050 px) (1872 x 1052 px).png
Brought to you by
Impacting Tomorrow Today

How Jewelers of America’s 20 Under 40 are leading to ensure a brighter future for the jewelry industry.

Silas Smith and his Responsible Design Challenge Winning Pendant
Events & AwardsDec 10, 2025
MJSA Names 2025 Responsible Design Challenge Winner

Silas Smith of Meridian Metalworks won the challenge with his pendant that blends Australian and American landscapes.

Weekly QuizDec 04, 2025
This Week’s Quiz
Test your jewelry news knowledge by answering these questions.
Take the Quiz
Sothebys orangy pink The Desert Rose diamond
AuctionsDec 09, 2025
‘Desert Rose’ Diamond Sells for $8.8M in Abu Dhabi

The sale of the 31.68-carat, sunset-hued stone was part of Sotheby’s first series of events and auctions in Abu Dhabi.

National Jeweler columnist and Smart Age Solutions CEO Emmanuel Raheb
ColumnistsDec 09, 2025
Holiday Sales Happen in December, Most Decisions Don’t

Most customers who walk into your store this month have made up their minds. Your job is to validate their choice, Emmanuel Raheb writes.

roseco-catalog.png
Brought to you by
Roseco Releases New Full-Line Catalog

Roseco’s 704-page catalog showcases new lab-grown diamonds, findings, tools & more—available in print or interactive digital editions.

Guzema Once Upon a Time Collection Campaign
TrendsDec 09, 2025
‘Once Upon a Time,’ Guzema Debuted Its Holiday Collection

The collection features characters and motifs from Ukrainian folklore, including an enchanted mirror and a magic egg.

Gemvision by Stuller MatrixGold 3.11
TechnologyDec 09, 2025
Gemvision Releases Updated MatrixGold

MatrixGold 3.11, the newest version of the jewelry design program, offers more flexibility, precision, and creative control.

Sign at the JA New York jewelry trade show
Events & AwardsDec 09, 2025
MJSA Showcase Pavilion Returning to JA New York

The pavilion will be part of the 2026 JA New York Spring show, scheduled for March 15 to 17.

Juell Kadet, former executive vice president of Rogers & Hollands
MajorsDec 08, 2025
Juell Kadet, a ‘Lifelong Pillar’ of Rogers & Hollands, Dies at 96

Kadet, a 1994 National Jeweler Retailer Hall of Fame inductee, helped grow the family-owned retailer in the Chicago area and beyond.

Lumia 2 smart earrings
TechnologyDec 08, 2025
You’ve Heard of Smart Watches and Rings; Meet Smart Earrings

Billed as the world’s smallest wearable, Lumia Health’s new smart earrings have a health tracker subtly embedded in the back.

Lionheart Wildflower Double Cocktail Ring
TrendsDec 08, 2025
Amanda’s Style File: Celebrating December’s Birthstones

Don’t let those with December birthdays feel blue. Help them celebrate their month with blue zircon, turquoise, and tanzanite.

Robinson Pelham Tsar Star Earrings in Blaze
CollectionsDec 05, 2025
Piece of the Week: Robinson Pelham’s ‘Tsar Star’ Earrings

The new pink sapphire version of the piece dances with its wearer in the brand’s “Icons After Dark” holiday campaign.

Pantone 11-4201 Cloud Dancer
TrendsDec 05, 2025
Pantone’s Color of the Year for 2026 Is … White

A choice that’s generated a lot of commentary, Pantone says “Cloud Dancer” marks a fresh start and encourages relaxation and creativity.

Stuller holiday 2025
MajorsDec 05, 2025
Stuller Releases ‘Wrapped in Wonder’ Campaign

The manufacturer’s holiday campaign features a gift guide filled with trending designs and jewelry that can be personalized.

Fabergé x 007 Octopussy egg and pendant
CrimeDec 04, 2025
Man Arrested After Allegedly Swallowing Fabergé Egg Pendant

The man was charged with theft, accused of ingesting the necklace while in a jewelry store in Auckland, New Zealand.

Exterior of renovated and expanded J.R. Dunn Jewelers
IndependentsDec 04, 2025
Step Inside JR Dunn Jewelers’ Giant New Store

The Florida independent expanded its store from 8,000 to 14,000 square feet, fulfilling the vision of its late co-founder, Jim Dunn.

DD-Email-Image-1872x1052 (1).jpg
Supplier BulletinDec 04, 2025
Introducing Shop Natural Day: A New Movement Celebrating Natural Diamonds

Sponsored by De Beers Group

G-Shock DWN5600 Ring
WatchesDec 04, 2025
Casio Shrinks its G-Shock Watch

The classic 5600 series G-Shock has been scaled down to about a tenth of its size, becoming a fully functioning watch ring.

Accredited Gemologists Association logo
Events & AwardsDec 04, 2025
AGA Announces 2026 Tucson Speaker Lineup

The association’s annual conference and gala will take place Feb. 4, 2026, during the Tucson gem shows.

 CBG logo
Events & AwardsDec 04, 2025
CBG Announces Speaker Lineup for 2026 Miami Event

The January show will include a workshop for jewelry retailers on implementing AI to strengthen their businesses.

Miley Cyrus and Maxx Morando Engagement Ring
TrendsDec 03, 2025
Miley Cyrus Debuts Edgy Engagement Ring

Fellow musician Maxx Morando proposed to the star with a chunky, cushion-cut diamond ring designed by Jacquie Aiche.

Costco store
Policies & IssuesDec 03, 2025
Costco Joins Growing Wave of Retailers Suing for Tariff Refunds

The retailer, which sells billions in fine jewelry and watches, is suing the Trump administration and U.S. Customs and Border Patrol.

Shoppers in a mall
SurveysDec 03, 2025
A Record 202.9M Shoppers Turned Out Thanksgiving Weekend

Black Friday is still the most popular shopping day over the five-day holiday weekend, as per the National Retail Federation’s survey.

Faberge The Winter Egg
AuctionsDec 03, 2025
Fabergé’s 'The Winter Egg' Achieves Record $30M

The historic egg, crafted for Russia's ruling family prior to the revolution, was the star of Christie’s recent auction of works by Fabergé.

×

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