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by Stockwatch Business Reporter

Two weeks after revealing impressive assays from a drill hole at its Las Vetas gold property in Colombia, CB Gold Inc. has toned down the excitement with, as requested by the British Columbia Securities Commission, restated assays including a top cut. A top cut reduces (or cuts) an uncommonly rich assay, usually a short intersection, to a lower assay -- say from several hundred grams per tonne gold to 50 g/t -- and then the average of it and other assays is recalculated.

In its earlier news release of Oct. 24, CB Gold reported a 114.98-metre interval of 7.57 g/t gold, including 2.09 metres of 316.67 g/t gold, but used no top cut in its calculation. There is no suggestion the company tried to conceal the narrow intersection of extraordinarily high gold.

Brent Cook, a well-known geologist, consultant and newsletter editor, explains in his Exploration Insights newsletter that top cutting assays reduces the influence an individual assay interval has on a much longer drill hole. He explains that an individual assay samples only a three- or four-inch width of a drill hole. These samples from the drill core are then crushed, pulverized and reduced to 30- to 50-gram samples for assaying. After completing the assays, the assay company gives the results to the mining company or perhaps its qualifed person. The company or its qualified person then reports the assays to reflect a grade over a certain length of rock, usually 25, 50 or 100 metres. There are times when a drill hole may go through a high-grade section, or completely miss, but either result is usually far from representative of the drill core. Mr. Cook explains, "True grade capping is a statistical treatment of assays usually used in resource calculations to constrain the effect of outlier high grades." He concludes the objective is not to let high-grade samples have greater influence on the estimate and produce an overly optimistic result. Mr. Cook pointed out to his subscribers on Oct. 30 that CB Gold did not use any top cut in its calculations. He removed the impressive 2.09-metre intercept from the company's 40.89-metre high-grade interval of 17.17 g/t gold and revealed a 38.8-metre interval of 1.04 g/t gold.

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