LETTERS TO THE EDITOR — Planned DHK bulk sample an

In “Economic pipes indicated at BHP-Dia Met project” (T.N.M., Sept. 27/93), you write of the BHP-Dia Met group’s apparent decision not to proceed with any further testing of the Point Lake discovery as a “bombshell,” supposedly lobbed into our camp.

The fact that DHK companies are proceeding with bulk testing of the Tli Kwi Cho target is based on data developed from core drilling at Tli Kwi Cho and not on any extraneous circumstance.

The decision to proceed was made after an analysis of all recovered diamonds and indicator minerals by Kennecott and RTZ staff and experts, drawn from their worldwide mining operations, which includes a producing diamond mine. If a comparison was made, as stated in the article, this comparison was confined to the micro-diamond counts only as reported by various operators. Such a comparison has its limitations because:

* the samples dealt with are small and therefore have statistical flaws; * laboratory tests and thermodynamic theory suggest that conditions of temperature and pressure conducive to the formation of fast-growing micro-diamonds may not be necessarily conducive to the formation of slowly growing, well-formed, clear, gem-quality diamonds (the profit core of any diamond mine);

* and, theoretical speculation suggests that micro-diamonds may actually be formed in the magma during the ascent and emplacement of the kimberlite itself and thus be somewhat removed from the formation and storage of gem-quality diamonds in the upper mantle.

To conclude, the best that can be said about a micro-diamond count was stated by Lakefield in a paper delivered in Toronto last spring at the annual convention of the Prospectors and Developers Association of Canada: “Of particular note, there are no cases we know of in which a pipe barren of macro-diamonds has a high micro-diamond content; and conversely, to our knowledge, there are no cases where a pipe has macro-diamonds and no micro-diamonds. The rate of ascent, depth of liberation from the mantle host and oxygen fugacity of the magma are only three factors which may have a significant impact on the degree of resorption and preservation of both macro-diamonds and micro-diamonds.”

It is apparent from the foregoing that only a bulk sample of sufficient size will determine the grade and quality of the diamond content of Tli Kwi Cho and that to proceed with a sample of 5,000 tonnes at this time, instead of a smaller one, is an expression of confidence in the overall data collected from Tli Kwi Cho.

Adolf Petancic

President, DHK Resources

Vancouver, B.C.