What Is the Second Largest Diamond
The second largest diamond is the Sewelô, a 1,174 carat Type IIb stone recovered in Botswana in 2019 by Lucara Diamond Corp from the Karowe mine. It ranks directly below the 3,106 carat Cullinan I, the largest clear diamond ever found. Sewelô is notable for its high value, large size, and modern sale process, which set a benchmark for how major rough stones are marketed and sold today Lucara Diamond Corp.
In terms of global rankings, Sewelô is the second largest gem-quality rough diamond discovered, and it is the largest stone recovered by Lucara using its X-ray transmission technology at Karowe. The stone was identified in November 2019, and its sale was handled through a structured process aimed at institutional and sovereign buyers, reflecting the growing role of technology and transparency in the high-end diamond market.
Origin, Discovery, and Mining Details
Sewelô was recovered at the Karowe mine in Botswana, a world-class diamond-producing region known for large, high-quality stones. Lucara Diamond Corp, a Canadian-based mining and technology company, operates the mine and has developed proprietary scanning systems to detect large rough diamonds during processing. The discovery was confirmed in 2019, and the stone was immediately secured and entered the company's valuation and sale pipeline Forbes.
Botswana's diamond sector is a major contributor to government revenue, and stones like Sewelô reinforce the country's position as a leading source of large gem-quality diamonds. Lucara's approach focuses on recovering high-value rough stones and selling them through controlled, data-driven processes, which helps reduce speculative pricing and increases visibility for buyers and regulators.
Ownership, Sale Process, and Market Impact
Lucara Diamond Corp retained ownership of Sewelô after its discovery and managed the sale through a targeted process designed to attract sovereign wealth funds, state-backed entities, and institutional investors. The company did not conduct a public auction, instead using direct negotiations and structured offers to match the stone with a buyer capable of supporting long-term value creation and security requirements.
The sale of Sewelô highlighted how large diamond transactions increasingly involve sovereign and institutional capital, with buyers focused on strategic reserves, branding, and long-term value rather than immediate resale. This trend has influenced how major mining companies present large stones, shifting toward transparent, data-rich sales processes and emphasizing provenance, cutting potential, and post-sale use SEC. The transaction also reinforced the role of technology in diamond discovery, with Lucara's scanning systems enabling the identification of stones that would previously have been discarded or overlooked during standard processing.