(ShareCast News) - Botswana Diamonds announced on Tuesday that a diamond has been found in the early stage of the re-analysis by Alrosa specialists of concentrate from large diameter drilling on kimberlite pipe AK21 on PL 260.The AIM-traded firm said it is a 1mm octahedron-shaped diamond.It had previously announced that two large diameter drill holes were completed on AK21 on Licence PL 260 in April.Eighty tonnes of samples were sent to a processing facility in South Africa, and control micro diamonds were included in the material, in line with best practice to detect inefficacies in the processing plant.The results from the laboratory demonstrated that test work was insufficiently robust as no diamonds were recovered, not even the control diamonds.Accordingly, Botswana Diamonds recovered the concentrate from the processing facility and re-analysed it using Alrosa mineralogists, who travelled from Russia to Botswana.The first 20kg re-analysed produced a 1mm octahedron diamond - a newly discovered diamond and not one of the control stones.A further 60kg of sample is currently being analysed, the company said."The Alrosa/BOD joint venture identified licence PL 260 in Orapa as having strong potential," said Botswana Diamonds chairman John Teeling."It had already identified anomalies which deserved attention."Moreover, historical drilling had found several diamonds, albeit not yet enough to be commercial grade."Teeling said the company now believed that there is commercial potential, so it has undertaken both a core hole and a LDD hole programme."The discovery of a 1mm diamond in the first 20kg of material is a positive development as we now know there are diamonds in the pipe."We have more work to do on the material."Teeling confirmed the current core hole drilling is on a known kimberlite, AK 22, which is close to AK 21."We have intersected the pipe and are pleased with the material being recovered."