Stellar Diamonds (LON:STEL) has started a new drilling programme on the Droujba kimberlite pipe near its operational Mandala diamond mine.
The nearby Mandala mine is one of Stellar’s two producers in Guinea. Stellar’s medium term strategy is to use these producing diamond mines to fund the development of its high-grade kimberlite projects in Sierra Leone and Guinea.
In total 20 holes will be drilled and the results will allow the company to model the kimberlite.
“Over the next few months we will be defining the geological model of the pipe to a depth of 150m and collecting representative samples for microdiamond analysis,” chief executive Karl Smithson said.
“The results of this work will enable us to model and forecast the macro-diamond (commercial) grade of the pipe which, if positive, will give us the incentive to undertake a larger-scale bulk sample of the kimberlite pipe.”
Bulk sampling would allow Stellar to determine accurate diamond grades and values.
Smithson added: “We will also drill some unresolved geophysical anomalies with the objective of discovering new kimberlites in proximity to Droujba."
The Droujba pipe was discovered in the early nineteen sixties and it was subsequently mined until 1964.
Historic reports put Droujba’s diamond grades as high as 200 carats per hundred tonnes, and a 270-carat stone was believed to have been discovered in the gravels near the pipe.
More recently a number of geophysical surveys have been carried out at Droujba, by Stellar and West African Diamonds.
The surveys showed that the pipe could be twice as big as previously mapped.
Now the 20-hole drilling programme, which will cover at least 3,000 metres, will test number of high-priority geophysical targets to see if they are part of these ‘undiscovered’ kimberlite.