Firestone Diamonds Plc, the London AIM-quoted diamond mining and exploration outfit, is upbeat about its drilling results at Tsabong project and say that they are “highly encouraging”, adding that it is now fast-tracking the bulk sampling to bolster confidence in the grade estimation.
Following the results on Thursday, Firestone Diamonds’ Chief Executive Officer, Phillip Kenny, said that bulk sampling for the micro diamonds is expected to commence in March, and it will involve ore from its MK1.
“This is a highly encouraging result from the first kimberlite to be evaluated by Firestone in the Tsabong field, particularly given the very large size of MK1.
“We have 83 kimberlites in our licence area and with 14 high interest kimberlites to be bulk sampled in 2008 and bulk sampling is expected to commence in March; we believe that the prospects for a significant economic discovery are good,” he said.
Kimberlites are a volcanic rock formation that took place some 2 million years ago in which diamonds are found within. Though there are many kimberlites rock formations in the world, very few of them contain some diamonds.
Tsabong is noted for its exceptionally large size kimberlites, in particular 180 hectares MK1 kimberlite, which is one of the largest known diamondiferous kimberlites in the country.
Firestones Diamonds made the statement last week after samples from its Tsabong project were submitted to SGS Minerals Services of Canada for micro diamonds recovery test.
A total of 117 micro diamonds greater than 0.75 mm were detected from a 561 kilograms of kimberlitic core treated.
“Furthermore, analysis of the individual samples indicates an increase in grade with depth, with samples MK1/4, although small, indicating a potential of 119 carats per hundred tones for the interval sampled.
“It should be noted that these are preliminary estimates, as between 200-400 micro diamonds are typically required to provide a grade estimate with the necessary levels of confidence,” the company emphasized.
“The data does indicate, however, that MK1 has the potential to have a significantly higher grade than was previously estimated based on the shallow drilling and limited evaluation carried out in the 1980s and it is very encouraging,” Firestone said.
The bulk sampling, which is expected to start this month, is expected to determine the grade estimates in an attempt to increase confidence in the project.
This follows an indication from a South African- based consultancy firm which indicated that the Tsabong project has a potential of yielding 1.1 billion tones of kimberlite to the depth of 1,000 meters.
The current work will entail the bulk sampling of the new two drilled holes, from the south-east and north-west lobes of MK1, which have been drilled to the depth of 524 meters and 490 meters, respectively.
The results from those two drilled holes are currently being analysed by SGS Minerals Services , South Africa, and the results are due during the second quarter of this year.
According to the preliminary information from Firestone Diamonds, the Tsabong project has a potential of producing 1.1 billion tones of kimberlite to the depth of 1,000 meters.
And with diamond price having tripled since the Tsabong field was discovered in the 1980s the economic viability of the area has been substantially improved, but only stones of US $ 100 per carat will support a large scale mining project.
As part of the plan, Firestone has installed a Dense Media Separation at Tsabong to treat ore from its areas of exploration. The plant will treat ore from all Firestone exploration sites including Jwaneng and Orapa areas. The ore from different mining explorations will be hauled with trucks to the sampling plant.
