Stellar Diamonds (LON:STEL) said it continued to make “strong progress” as it advances its Droujba kimberlite pipe in Guinea through the bulk sampling phase.
It processed a total of 2,023 dry tonnes of ore in its phase-two programme from eight separate pits.
In doing so it returned grades of 70 carats per hundred tonnes from the first sample and 109 cpht from the second.
The largest gem quality diamond was 6.9 carats, while there were other stones of 9.55, 7.68, 5.55, 4.25 and 4 carats.
Chief Executive Karl Smithson said: "The early results from the first phase-two samples processed are very encouraging, with high grades and the presence of larger gem quality diamonds than have previously been recovered from the earlier bulk sampling.
“Furthermore, the recovery of large stones up to 9.55 carats from the small volume of kimberlite processed is indicative that Droujba may have a coarse stone size distribution.
“Once the processing has been completed the diamond parcel will be exported to Antwerp for valuation and upgrading of the independent resource model.
“We remain confident of the potential that Droujba offers and we continue to focus on the near term objective of increasing the size and confidence level of the presently defined 2.5 million carat inferred resource."
Stellar also revealed that bulk sampling nearby Katcha kimberlite will take place.