De Beers grades reasonable

Vancouver — An independent valuation of stones collected from the 2000 exploration program at the Fort a la Corne project in Saskatchewan has confirmed the diamond grades of the No. 141 and No. 122 kimberlite bodies for partners Kensington Resources (KRT-V), De Beers Consolidated Mines, and Cameco (CCO-T).

The study, completed by Antwerp-based WWW International Diamond Consultants, concluded that given the size of the samples, the changing diamond market and price fluctuations, the De Beers valuations and their associated modelling are reasonable.

De Beers tabled the results earlier this year based on a limited parcel of stones weighing 21.06 carats — recovered from a 251.8-tonne mini-bulk sample taken last year from kimberlite 141. The modeled grade for the body came in at 18 carats per 100 tonnes, with a best-fit value of US$153 per carat, or US$28 per tonne. Kimberlite 122 has a predicted grade of 7.5 carats per 100 tonnes, with a best-fit value of US$144 per carat, or US$11 per tonne based on a parcel of diamonds weighing 17.31 carats.

The partners are in the midst of a 10-hole, large-diameter drill program aimed at collecting 1,100 tonnes of kimberlite for further testing.

The Fort la Corne project comprises 255 sq. km of ground east of Prince Albert and contains 69 confirmed kimberlites. At least 49 of the bodies are diamondiferous, and 34 have yielded stones larger than 1 mm in at least one dimension. De Beers and Kensington each hold a 42.25% stake, and Cameco and its wholly owned subsidiary, UEM, hold the remaining 15.5%. The 2001 exploration program has been funded by Kensington, De Beers, and Cameco at a cost of $4.79 million.

The first phase of this year’s program saw completion of 16 NQ-sized core (diameter of 46.4 mm) for a total of 2,413 metres of kimberlite intersections on the 140, 141 and 150 bodies. The goal was to assess the zonation pattern in the kimberlites and to refine the geological models for each body.

The Fort la Corne area is different from other kimberlite fields because it is almost entirely intact. When the pipes were first emplaced 100 million years ago the area was at the edge of a vast sea that covered the central portion of North America. The pipes were buried in sediments which became rock. Over time, erosion stripped the overlying rock layers and revealed an almost intact kimberlite field. Kimberlites in the Territories are younger, but have been eroded to deeper levels and have smaller surface expressions.

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