Trustco unearths mega diamond
New find
A 391.47-carat diamond was discovered in Sierra Leone's Kono district.
Trustco Group Holdings this week announced the findings of a recent examination of a 391.47-carat diamond recovered by Meya Mining in Sierra Leone. Trustco holds a 19.5% interest in Meya, which operates under a 25-year exclusive diamond mining licence in the Kono district.The 391.47-carat diamond was part of a 515-carat rough diamond recovered in the Meya River kimberlite domain on Tuesday, 20 August, in the first of 16 domains targeted by Meya. Along with two smaller fragments weighing 105.43 carats and 18.11 carats, this marks the second significant find from the region, confirming its potential as a source of high-value diamonds.
A detailed examination, conducted by Dr Evan Smith of the Gemological Institute of America (GIA), confirmed the diamond as Type IIa, a classification that indicates high purity due to the absence of nitrogen. Further analysis showed the diamond is part of the CLIPPIR variety (Cullinan-like, large, inclusion poor, pure, irregular, resorbed), similar to some of the world’s most valuable diamonds.
According to the examination report, the diamond contains metallic inclusions, mainly iron-rich metals, which suggest it formed deep in the earth, between 360 and 750 kilometres below the surface. Despite these inclusions, large parts of the stone remain clear, making it an important geological find. The discovery of this CLIPPIR diamond at the Meya mine confirms that the area contains large Type IIa diamonds.
Extraordinary landscape
Trustco deputy CEO Quinton Z van Rooyen said the recovery of this CLIPPIR diamond sheds light on Meya's extraordinary geological landscape. "As the diamond world contemplates the eventuality of a 5 000-carat stone, our recent find indicates that Meya's unique geology positions us well for potentially historic discoveries in the future.”
On 5 June, shareholders were informed that Z Star Mineral Consultants, an independent consulting firm, estimated the in situ resource of Meya River Domain at US$763 million. This Meya River domain accounts for less than 3% of the overall Meya Mining project potential
resources.
Additionally, on 2 September, shareholders were advised that the NI 43-101 technical report for the Meya Diamond Mine Project was published, offering a preliminary economic assessment (PEA). The PEA showed promising economic potential with a post-tax internal rate of return (IRR) of 65% and a post-tax net present value (NPV) of US$95.1 million at a 10% discount rate over a projected seven-year mine life.
These reports also noted that the estimated value of diamonds recovered from bulk samples and run of mine production of the Meya River domain, which were sold at public auctions, is US$380 per carat.
This estimation excluded the sale of the 476 carat Meya Prosperity diamond (US$34 664 per carat) or several subsequent large stones found due to their distinct nature. The valuation matrix currently used to assess Trustco's 19.5% stake in Meya Mining, at US$110 million, may be adjusted in the future to account for these historical exceptional finds. "Shareholders are advised that this could affect future valuations," Trustco said.
Meya Mining is now focused on improving its recovery process to prevent breakages of large diamonds in the future. The company is working with its engineering and processing partners to upgrade the plant and increase its capacity to recover large diamonds intact. This discovery strengthens Trustco’s mining portfolio, but also highlights Sierra Leone’s position as a key player in the global diamond market.