Stellar Diamonds (LON:STEL) this morning delivered what it described as “encouraging” results from the first phase of its bulk sampling programme at the Droujba kimberlite pipe in Guinea.
The initial grade has been calculated at 60 carats per hundred tonnes, which includes stones at 13.8 carats, 6.06 carats, 3.75 carats and 2.9 carats.
The re-processing of tailings is likely to increase the grade further, Stellar told investors.
In total, 448 tonnes of diamond bearing kimberlite rock were processed, which yielded 268.45 carats of diamonds.
The company remains on track to deliver a maiden resource estimate by the end of next month.
Chief executive Karl Smithson said: "The first two bulk sample results are very encouraging, with an initial grade of 60 carats per hundred tonnes being realised from initial processing, which is consistent with the expectation of high grade.
“Additionally, the recovery of a number of large stones, including a 13.8 carat and a 6.06 carat stone, from a relatively small parcel of 268 carats of diamonds, suggests a coarse size distribution to the diamond population.
“Sample processing is progressing well and we expect to have the full results available during March.
“We remain on track for delivery of the maiden resource statement for the Droujba pipe by the end of March and I look forward to updating shareholders as we progress."
Stellar also owns the Tongo project, which is in a renowned diamond mining area of Sierra a Leone.
Its shares rose sharply after bulk sampling results last month from Dyke 1 at Tongo that were described as “excellent”.
The grade was 121 carats per hundred tonnes with an average diamond value of US$185 per carat, while microdiamond analysis indicated “encouraging size distribution”.
Initial resource drilling of a 1.9 kilometre section of the 2.5 kilometre long Dyke 1 kimberlite was completed in December.
The remainder will be drilled during the next phase of resource definition.
The company rates as one City broker Daniel Stewart’s top picks for 2012.
Its sum of the parts valuation of the group comes out at 21 pence a share (current price 6 pence).