Paragon Diamonds in positive Lesotho bulk sampling, drilling programme

Paragon Diamonds said that its recently commenced Motete Dyke bulk sampling and drilling programme, in Lesotho has yielded 97 carats of diamonds and 1,404 individual stones.
It said in a statement that the largest stone recovered was 0.91 carats.
A further sample of 336.92 tonnes of mixed kimberlite with basalt contamination was processed over 10 days, and the Dense Media Separation (DMS) tailings were re-crushed and re-treated twice.
After excluding for over-size, removal of basalt contaminant, and un-crushed material, 217.14 tonnes of pure kimberlite, at 19.88 percent moisture content, for 172.37 dry tonnes were processed to -1 mm and the diamonds recovered.
The recovered grade calculates at 56.2 carats per hundred tonnes (cpht).
“This recovered grade from the bulk sample plant is as expected when compared to the micro-diamond model, with quasi-100 percent correspondence for diamonds above 2 mm in size,” it said.
“Below 2 mm down to 0.85 mm (this range would include all stone that could be considered commercial), the plant recoveries fall well below model, with only 48 percent of predicted carats below 2 mm and just 3 percent of predicted carats from 1.18 mm down to 0.85 mm recovered, using the model as a reference.”
Paragon said it intends to reprocess the tails in due course to recover some of these smaller stones, which should increase the grade.
The quality of the diamonds recovered was generally high, with abundant clear white dodecahedra encountered in the majority of size fractions.
“Whilst the average stone size of the Motete diamonds is smaller than those from the Lemphane Kimberlite, the current demand for smaller good-quality stones is high, riding on the back of the buoyant watch and accessory jewellery market,” it said.

Mathew Nyaungwa, Editor in Chief of the African Bureau, Rough&Polished