Operations
The World's Largest
Kimberlite Pipe
Williamson Diamonds Limited operates the Mwadui mine, one of the oldest continuously operating diamond mines in the world — famous for producing rare, high-quality "bubblegum" pink diamonds.
WDL operates across 146 hectares, combining open-pit mining with advanced tailings re-treatment to sustainably extract and process high-grade diamonds. As of May 2025, the operation transitioned to 100% Tanzanian ownership, after Petra Diamonds sold its 63% stake to Pink Diamonds Investments, an affiliate of Taifa Group.
Five Stages, One
Continuous Operation
Every tonne of ground moved at Mwadui passes through the same disciplined sequence from first blast to final sort. Nearly all technical roles engineers, technicians, and specialists are held by Tanzanian nationals, with local staff making up 99.8% of the technical workforce.
Open-Pit Mining
Our core operation involves a massive open-pit excavation currently reaching depths of approximately 90 metres. Using a fleet of heavy-duty excavators and haul trucks, we move millions of tonnes of ore annually. Technical teams use precision blasting and geological mapping to access the most diamond-rich sections of the kimberlite pipe.
Modern Processing Plant
Once extracted, ore is transported to our on-site treatment facility. Our processing cycle includes crushing & scrubbing to break kimberlite into manageable sizes, Dense Medium Separation (DMS) using gravity-based technology to separate heavy minerals from waste rock, and X-ray recovery — state-of-the-art technology that sorts diamonds with maximum efficiency and minimal breakage.
Tailings Re-treatment
In addition to fresh ore, WDL re-processes "tailings" — material previously mined that may still contain smaller or overlooked gems. This maximizes the value of every tonne of earth moved while minimizing our environmental footprint.
Quality Control & Sorting
Every diamond recovered at WDL undergoes rigorous internal sorting. We are globally recognized for our rare Type II pink diamonds, sorted and valued under strict international standards before entering the global market.
Infrastructure & Security
The operation is a self-sustaining ecosystem, with its own power supply, water management systems and a high-security perimeter. We prioritize the safety of our 1,100+ employees through world-class occupational health and safety protocols.
A Mining Operation Built for the Long Term
Operational excellence is only half the story — see how that same discipline extends to the environment and the communities around Mwadui.
Explore Sustainability