The Ministry of Mines and Mineral Resources and the National Minerals Agency announced on Monday the recovery of a 391.45-carat diamond from the Meya Mine in Kono district, eastern Sierra Leone. This is the second exceptional diamond recovered from the Meya River kimberlite domain.
The diamond, recovered on August 20, originated from a 514.99-carat diamond broken into three pieces (391.53 carats, 105.43 carats, and 18.11 carats). In November 2017, Meya Mining recovered a 476-carat Type IIa diamond (the Meya Prosperity) during its initial bulk sampling program.
The recovery of this large, superdeep Type IIa diamond is geologically significant, as these diamonds are known to originate from deeper within the earth’s lower mantle, at depths of approximately 750 km below the surface.
According to Casey Hetman, P.Geo. from SRK Consulting, large Type IIa diamonds sampled from the lower mantle and transported to the surface at Meya have a better chance of remaining intact during emplacement close to the surface. This is because they are not subjected to explosive fragmentation processes related to pipe development, as they have been emplaced within dykes at Meya.
Both exceptional stones were detected and recovered by the company’s bespoke processing plant, designed and constructed by Consulmet (South Africa). The specific technology deployed to enable the recovery of these large diamonds is from Tomra Sorting Solutions in Germany.
Jan Joubert, CEO of Meya Mining, expressed his optimism about the company’s latest recovery, stating, “Only four mines in the world infrequently recover these exceptional 500 carat diamonds. The fact that Meya has recovered two 500 carat Type IIa diamonds after treating only 84,195 tonnes of competent kimberlite from the Meya River domain suggests that there is a high probability of recovering more and possibly bigger diamonds once the mine reaches steady-state production of 500,000 tonnes kimberlite throughput per annum.”
He further emphasized the company’s priority to ensure the recovery of these high-value stones intact, stating, “We will work closely with our engineering and processing partners to upgrade the plant, eliminate breakages and increase its capacity to recover exceptionally large diamonds.”
This recovery marks the 6th time an exceptional diamond has been recovered from the area, highlighting Sierra Leone’s geo-economic potential, especially as an exceptional diamond producer. Since 1945, no less than 6 of the largest diamonds recovered globally came from Sierra Leone.
Julius Daniel Mattai, Sierra Leone’s Minister of Mines and Mineral Resources, expressed his hope that “the discovery of the 391-carat diamond would once again alert the world to Sierra Leone’s mineral resource potential and engender a renewed interest in investing in the country’s mining sector.” He also commended the company’s transparent approach to determining the market value of this stone and maximizing the economic distribution to all key stakeholders.
