The recently discovered Hearne and Tuzo kimberlite pipes on the AK property in the Northwest Territories are diamondiferous.
Monopros, a wholly owned subsidiary of De Beers Consolidated Mines (DBRS-Q), has recovered 324 diamonds by performing caustic fusion analysis on 132 kg of kimberlite core from the Hearne pipe. The diamonds were recovered from six 22-kg samples taken from different intervals in the hole.
Thirty-three of the stones had a screen size larger than 0.5-by-0.5-mm, representing 10.2% of the diamonds recovered. By comparison, a 528-kg sample from the 5034 pipe yielded 88 of 1,653 diamonds larger than 0.5 by 0.5 mm screen size (or 5.3%). De Beers classifies microdiamonds according to various square mesh aperture screen sizes.
The two largest diamonds from the Hearne pipe were 20 points each, or 0.2 carat (100 points equals 1 carat), whereas 14 diamonds were greater than 1 point, or 0.01 carat.
The Tuzo pipe yielded 403 diamonds from a composite of six samples weighing a total of 124 kg. Thirty-six of the diamonds were larger than the 0.5-by-0.5 mm screen size, and represent 8.9% of the recovered stones. The largest diamond recovered was 1.56 carats, whereas 13 diamonds were greater than 1 point, or 0.01 carat.
The AK and CJ properties are held 50% by Mountain Province Mining (MPV-V), 40% by a wholly owned subsidiary of Glenmore Highlands (GMH-A), and 10% by Camphor Ventures (CFV-V).
Mountain Province and Glenmore’s subsidiary are scheduled to merge by the end of October. The amalgamated company will retain the name Mountain Province Mining and hold a 90% interest in the properties.
Monopros can earn up to a 60% interest in the AK-CJ properties by funding exploration and a bulk-sampling program on one or more kimberlites, completing a feasibility study and funding development through to production.
Both the Hearne and Tuzo pipes, as well as the Tesla pipe, were discovered after Monopros launched its drilling program in May. All three are in the vicinity of the 5034 kimberlite pipe.
The Hearne pipe is 1.1 km southwest of the 5034 pipe, Tesla is 1.8 km northwest of 5034, and Tuzo is 700 metres northeast of the 5034 pipe and 760 metres southeast of Tesla.
The Tesla pipe has yielded 109 diamonds from a composite 66-kg core sample.
Eight of the diamonds were larger than the 0.5-by-0.5-mm screen size. Caustic fusion results from the Tuzo pipe are expected shortly.
The 5034 pipe contains a drill-indicated resource of 20 million tonnes, to a depth of 350 metres. Recent evaluations by De Beers on a small parcel of diamonds exceeding 1.65 mm in size averaged US$55 per carat. The grade of those diamonds is 1.5 carats per tonne; the preliminary value, US$82.50 per tonne.
A mini-bulk sampling program, scheduled for the winter, will test all of those pipes.