DiamondCorp (LON:DCP) this morning revealed a sharp improvement in the grade recovered from the historic Lace Mine in South Africa.
Recoveries have improved to around 22 carats per hundred tonnes from 13.76 carats at the time of the last update a little over a month ago.
It follows the company’s move into less diluted kimberlite and is based on a 1,533 tonne sub-sample from the current bulk sampling programme.
Chief executive Paul Loudon said: “We continue to be pleased with the results from the sampling, and look forward to reporting the results from the higher grade zones being sampled in the coming weeks.”
Separately, the group said drilling contracts have been awarded for both additional core drilling and large diameter drilling on kimberlites J-01 and J-05 at the Jwaneng South, Botswana. Drilling is expected to get underway next week.
The objective of this particular programme is to obtain a better understanding of the geometry and geology and return a preliminary diamond grade of both kimberlites by the end of the year.
Meanwhile at Lace, Diamond Corp has processed 1,235 carats of diamonds, and he biggest is still a 16.08 non-gem quality diamond to date.
More importantly the quality remains consistent with an initial parcel valued at US$205 a carat last month. So far 40 per cent of the diamonds recovered have been greater than a third of carat and more than 80 per cent have been of gem quality.
The improvement will come as little surprise to management as sampling of the Lace kimberlite started on what’s described as the “stony ground side of the pipe”, where waste dilutes the grade.
The bulk sampling activities are progressively moving in a north-westerly direction where in the past the best recoveries have been reported.
Full-scale mining will start with the higher grades and work out to the lower grades.
The results of the bulk test, meanwhile, will determine both the carat value of the Lace diamonds and the grade of kimberlite zones to be mined. These results will be the basis of the plan for the first mining.
So far it is 37 per cent of the 30,000 tonne bulk sample has been carried out and less than 30 per cent of the pipe has been sampled.