Lucara Diamond Corp. pulled a fist-sized stone from the Karowe mine in Botswana’s Boteti District around August 19, 2024, and set it on a table in front of then-President Mokgweetsi Masisi. The first scale reading was 2,492 carats. That number made the rough the second-largest gem-quality diamond ever taken from the ground, behind only the 3,106-carat Cullinan recovered at Premier Mine in South Africa in 1905. The AEGIS Alliance first wrote the discovery as a spectacle. The file that remains is a sale. The stone has a name, a cleaned weight, a laboratory exam in Gaborone, and a buyer whose identity Lucara still will not print.
Karowe sits about 500 kilometers north of Gaborone in a kimberlite pipe that has become a factory for giants. Lucara, a Canadian company, installed a Mega Diamond Recovery X-ray line in 2017 specifically so large crystals would be spotted before crushers smashed them into ordinary goods. CEO William Lamb and Botswana managing director Naseem Lahri credited that circuit when they showed the stone. Type IIa diamonds, which lack nitrogen and make up less than 2 percent of world production, are the usual headline class at Karowe. Later laboratory work on this particular crystal was more complicated than the first press release.
Karowe’s Habit of Making Famous Rocks
Before this recovery, Karowe had already produced Lesedi La Rona at 1,109 carats, Sewelô at 1,758 carats, and the 813-carat Constellation, which sold for about $63.1 million. Those names are not trivia. They are the reason Lucara could raise money for a recovery plant that other mines treat as a luxury. Most diamond ore is processed as if the valuable crystals will be small. Karowe is processed as if the valuable crystals might be the size of a baked potato. That bet paid again in August 2024.
Masisi held the stone for cameras and said God is good. Officials talked about putting the rough on public view before any sale. Museums and cutting houses made the usual noises. Large Type IIa goods can be cleaved into a suite of polished stones that carry a royal or auction-house story for decades. They can also sit in a vault while the owner waits for a price that matches the press conference. Lesedi La Rona took nearly two years before Graff paid in the neighborhood of $53 million. That delay is the template this file followed.
Motswedi, the Cleaned Weight, and the GIA Bench
Lucara opened a national naming contest on November 22, 2024. More than 39,000 entries came in. The winning word was Motswedi, Setswana for a spring of water or a source. The submitter received 100,000 pula and a tour of the mine. A second Karowe giant of 1,094 carats, found weeks later, was named Seriti. After cleaning, Motswedi officially weighed 2,488.32 carats. The four-carat drop is ordinary. Surface skin, attached kimberlite, and cleaning water come off. The number that matters for history is still north of 2,400.
The Gemological Institute of America examined Motswedi in Gaborone and published its notes in 2025. GIA called it the largest known single crystal the institute had tested. The measured dimensions were 106.3 by 71.6 by 53.8 millimeters, a little over a pound. Eleven small fragments totaling 1.50 carats had come off. Two of those pieces weighed 0.75 and 0.47 carat. The main crystal was transparent and gem-quality with a light brown color that GIA said was likely emphasized by the size and by foreign material in fractures. The fragments were essentially colorless. On type, GIA described Karowe’s large goods as Type IaB or a mix of IaB with IIa, a more precise sentence than the first corporate adjectives.
That laboratory paragraph is the difference between a press release and a stone. Color, type, and fracture fill decide whether a 2,488-carat rough becomes a museum object, a suite of D-color polished diamonds, or a brown collector piece with a famous name. Lucara did not publish a cutting plan. The company did not have to. It only had to find a buyer.
The Two-Year Wait and the Undisclosed Check
The rough sat unsold through 2025 and into 2026. Diamond prices for large goods were not the roaring market of the Constellation years. Manufacturers were picky. Sanctions, lab-grown competition, and a soft Chinese bridal market all argued for patience. Lucara’s August 7, 2026, quarterly results finally said Motswedi sold in the second quarter of 2026. National Jeweler and Business Insider Africa reported the sale as part of about $41 million in quarterly diamond revenue. The buyer was not named. The price for the stone itself was not broken out.
That silence is a choice. A public auction would have produced a headline number. A private treaty sale lets a cutter or a royal client avoid teaching every rival what the bid was. It also leaves Botswana’s public arguing in the dark about whether the country captured the value of the second-largest diamond ever mined. Diamonds still account for a huge share of Botswana’s export earnings and a large slice of government revenue. Debswana, the De Beers joint venture, remains the center of gravity. Karowe is the independent sideshow that keeps producing the stones people remember.
Readers who follow resource politics on The AEGIS Alliance 国际新闻. desk already know the pattern. A poor country’s dirt makes a rich company’s quarterly. The naming contest is the pageant. The term sheet is the government. Botswana has spent decades trying to keep more of the cutting and more of the marketing onshore. A stone this size tests that project. If Motswedi is cleaved in Antwerp or Dubai, the spring of water is a brand, not a factory.
Why a Single Crystal Still Moves Markets
Large diamonds are not priced like run-of-mine goods. They are priced like paintings. Provenance, intact recovery, and a presidential photo op all add zeros. The Cullinan became the British Crown Jewels. Lesedi La Rona became a Graff marketing campaign. Motswedi now belongs to someone who has not agreed to be identified. Until that owner loans the rough to a museum or publishes a cutting diagram, the public story stops at the GIA measurements and the Q2 2026 line in Lucara’s release.
There is a second, quieter market fact. Karowe’s X-ray recovery line is a reminder that most historic giants were found by accident or destroyed in crushers. The 1905 Cullinan was spotted by a mine superintendent who thought he was looking at a piece of glass in the wall. Motswedi was spotted by a machine built to keep that from happening. Mining technology is the unglamorous half of the romance. Without the 2017 plant, this article is about a pile of smaller brown goods.
Lab-grown diamonds have taken the low and middle of the jewelry case. They have not taken this. A 2,488-carat natural crystal with a GIA file and a Setswana name is not competing with a reactor in Guangdong. It is competing with the last twelve historic roughs and with the patience of whoever writes the check. That is why Lucara could wait almost two years. That is why the sale price is still a secret.
What The AEGIS Alliance Is Watching Next
Three questions remain open. Who bought Motswedi. Whether the rough will be cut or kept whole. Whether Botswana’s next giant stays in the country long enough for the public to see it without a velvet rope in another hemisphere. Seriti, the 1,094-carat sibling, is the next name on that list. Karowe is still in ore.
Related reporting from The AEGIS Alliance includes coverage of other resource stories on the 科学 desk and the international wire. The AEGIS Alliance treats a presidential photo with a rock as the start of a paper trail, not the end of one. The second-largest diamond ever mined now has an owner. The public still does not know the price.
