Largest Diamonds by Weight and Origin
The largest diamonds are ranked by polished or rough carat weight, with stones over 1,000 carats drawing global attention from miners, auction houses, and investors. The Cullinan, discovered in South Africa in 1905, remains the largest gem-quality rough diamond at 3,106 carats, and its polished fragments are part of the British Crown Jewels and other royal collections, as detailed by major gemological sources and auction records Forbes. The Lesedi La Rona, found in Botswana in 2015, is the second-largest gem-quality rough diamond at 1,109 carats and was sold by Lucara Diamond Corp to a syndicate that includes Graff Diamonds and the Botswanan government, with cutting and polishing underway to produce high-value stones Lucara Diamond Corp.
Key Rough Stones and Their Current Status
The third-largest gem-quality rough diamond is the Excelsior, a 995-carat stone found in South Africa in 1893, which was cut into multiple smaller gems now held in private and museum collections. The fourth-largest, the Incomparable, weighed 890 carats when it was found in the Democratic Republic of the Congo in the 1980s and later became a 407-carat internally flawless diamond sold at auction, with details tracked by auction houses and gemological institutes Gemological Institute of America.
Major Owners, Miners, and Auction Records
Large diamonds are often sourced by major mining companies such as Lucara Diamond Corp, De Beers, Alrosa, and Rio Tinto, which operate primary deposits in Botswana, South Africa, Russia, and Canada, and sell rough stones through tender processes, private sales, or high-profile auctions. Lucara's Karowe mine in Botswana has produced several record stones, including the 1,174-carat Sewelo rough diamond sold to a Louis Vuitton-backed consortium in 2024, highlighting how private equity and luxury brands now participate in large-diamond ownership Lucara Diamond Corp.
Auction Houses and Polished-Value Chains
Sotheby's and Christie's regularly feature large polished diamonds in their jewelry sales, with per-carat prices rising for stones above 100 carats due to scarcity and demand from collectors and sovereign wealth funds. After cutting and polishing, some of the largest rough diamonds yield stones that are graded by the Gemological Institute of America and sold to elite jewelers or set in museum displays, with ownership often remaining private or held by state entities Sotheby's.
Current Rankings and Market Impact
As of the newest public data, the top 10 largest diamonds include the Cullinan, Lesedi La Rona, Excelsior, Incomparable, Star of Sierra Leone, Millennium Star, Woyie River, Lesotho Legend, Graff Lesedi La Rona, and the Sewelo, with rankings based on rough or polished weight depending on the source and cutting outcomes. These stones influence the high-end diamond market by setting per-carat price benchmarks, attracting institutional buyers, and driving investment in exploration and mining technology across Botswana, South Africa, Russia, and Canada U.S.