Stellar Diamonds said that the re-processing of bulk sample tailings at its Tongo kimberlite dyke project in Sierra Leone has yielded additional diamonds and increased the average grade to 155 carats per hundred tonnes (cpht) from 120cpht.
It said in a statement emailed to Rough&Polished that processing to date had now yielded 843 carats.
The diamonds from the re-crush were typically of high colour and quality, although they had an overall smaller average stone size than the first pass diamonds, since the crushing setting was reduced during the re-processing, it said.
“Tongo continues to yield excellent results underpinning the project’s significant potential. The reprocessing of sample tailings has yielded additional diamonds that have further enhanced the average bulk sample grade to 155 cpht,” said company chief executive Karl Smithson.
“This grade compares very favourably with the previously calculated resource grade of 120cpht and should impact positively on project economics as well as the resource size, which is currently independently estimated at 1.1 million carats (JORC compliant).”
He said the final bulk sample to complete the 1,000 carat parcel was currently being extracted and processed.
The company was expecting the final grade and value data to be available in August.
Mathew Nyaungwa, Editor in Chief of the African Bureau, Rough&Polished
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