Lucara Diamond (TSX: LUC) has found an unbroken 341-carat white gem-quality rock at its Karowe mine in Botswana, with analysts estimating it could fetch more than US$10 million.
The Vancouver-based miner said the diamond was recovered over the Christmas period from milling of ore coming from the southwestern quadrant of Karowe's South Lobe.
The diamond is the 54th stone over 200 carats recovered at Karowe since it began commercial operations in 2012.
The find builds on previous historic recoveries that include the 342-carat Queen of the Kalahari, the 549-carat Sethunya, the 1,109-carat Lesedi La Rona found in 2015, and the 1758-carat Sewel??, recovered in 2019.
Beyond Sewel??, the only larger diamond ever unearthed is the 3,106-carat Cullinan Diamond, discovered in South Africa in 1905. The Cullinan was later cut into smaller stones, some of which now form part of British royal family's crown jewels.
BMO Capital Markets analyst, Ray Raj, said the based on past prices for similar size stones, the new diamond could sell for more than $10 million.
"The continued recovery of the significant high value stones from the South Lobe further highlights the importance of the Karowe underground expansion." he wrote in a research note to clients.
Raj also highlighted a "significant" revenue potential for Lucara this year, with the sales process from the 549-carat and the 998-carat diamonds recovered in 2020 expected to be completed in 2021.
Botswana renewed Lucara's mining licence in early January for another 25 years. The move allows the company to move the Karowe's underground expansion project to its execution phase.
Moving the operation underground will cost $514 million. It is expected to take five years and extend Karowe's productive life by 20 years - until 2040.
The development will allow Lucara to exploit the highest value part of the orebody first and generate over $5.25 billion in gross revenue.