Letters to the Editor Assay techniques not to be blamed

I was somewhat puzzled by statements made in your article “Calpine cuts 96 ft of 0.7 oz gold” (N.M., Nov 7/88).

No doubt the folks at Calpine Resources were very gratified to see their average grades jump 50% (from 0.22 oz to 0.31 oz) simply by changing from atom ic absorption to fire assay but one is prompted to ask which grade is the right one and why such a large difference?

As a commercial assayer, I can guarantee you my customers would want some kind of explanation, especially about your next statement that the further assays done “were composite assays in which the atomic absorption assays were converted to fire.”

Now that really burns me up, so to speak (pun definitely intended). Taken at face value, your article seems to be pointing to atomic absorption as the low-down villain whose salvation is found by a miraculous conversion to higher fires, whatever that means.

We do many thousands of assays by both techniques (fire assay and atomic absorption) and both have definite merit in the hands of knowledgeable assayers but let’s not get side-tracked into blaming assay techniques when the problem lies elsewhere. George Duncan President Accurassay Laboratories Limited Kirkland Lake, Ont.