Lucara’s rare blue diamond at Karowe: stockpile value and UG transition lens
Reviewed by Tom Sullivan

First reported on MINING.com
30 Second Briefing
Lucara Diamond has recovered a 36.92-carat Type IIb blue diamond from surface stockpiled ore at its 100%-owned Karowe mine in Botswana, using X-ray transmission sorting that has already delivered five stones over 100 carats in 2026. The find reinforces the economic value of Karowe’s stockpiles as open-pit mining winds down before June and the operation transitions to underground production. A completed feasibility study for the underground expansion outlines potential recovery of 4.5 million carats over 10 years, with Karowe currently yielding about 300,000 high-value carats annually.
Technical Brief
- X-ray transmission sorting at Karowe is sensitive enough to recover a 36.92-carat Type IIb diamond.
- The blue diamond was liberated from previously mined surface stockpiles rather than fresh run-of-mine ore.
- Karowe’s stockpiles have already produced five individual stones exceeding 100 carats in 2026 alone.
- Open-pit extraction at Karowe is scheduled to cease before June, forcing a near-term shift in ore logistics.
- Mill feed continuity will depend on stockpile reclaim systems while underground infrastructure ramps to commercial output.
- Historical recoveries include the 1,758-carat Sewelô, 1,109-carat Lesedi La Rona and 813-carat Constellation, confirming coarse-fragment size distribution.
- Despite global diamond market weakness and lab-grown competition, Lucara is concentrating capital on Karowe as a single flagship asset.
Our Take
Lucara Diamond’s 100% ownership of Karowe in Botswana gives it full exposure to value upside from any further large or coloured stones recovered during the transition from open pit to underground, unlike many African diamond operations in our database that are structured as state-linked joint ventures.
The feasibility study expectation of 4.5 million carats over a 10‑year underground life signals that maintaining recovery of high-value stones will be critical to project economics, putting a premium on processing and sorting performance for stockpiled ore as open-pit mining winds down in the next two months.
American Rare Earths’ Halleck Creek project in Wyoming, ranked among the world’s top 10 rare earth projects in 2023, underlines how both Botswana and the United States are featuring in our recent coverage as hosts to ‘tier-one’ style assets in niche commodities (diamonds and rare earths) rather than bulk base metals.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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