The gem-quality diamond is the largest recovered by Lonrho since it began treating diamond-bearing alluvial gravels through its dense media separation plant this past year, the company said. The diamond is twice the size of the 22.25-carat diamond found during the company’s bulk sample in November 2010.
“While this diamond has been recovered from the alluvial gravels, it is clearly derived from a nearby kimberlite pipe source,” Lonrho’s managing director Miles Kennedy said. “The task ahead of us over the next 12 to 18 months will be to find the source, or sources, shedding incredible diamonds of this size. The source is likely to be far richer than any of the alluvials.”
To date, Lonrho has recovered 102 diamonds from its most recent bulk sampling, weighing 173.85 carats from 339 cubic meters of alluvial gravels for an average grade of 51.2 carats per 100 cubic meters.
The Lulo project is located 150 kilometers west of ALROSA’s Catoca diamond mine in Angola.