IS THIS A GRAB, OR "GAB" SAMPLE?

Grab Samples

As the name suggests, this sample is something more or less collected at random from an outcrop, or as float, or from a dump, heap, scattered pile, or passing load. Grab samples usually are evaluated only to show the presence, or absence, of minerals or economic importance, or to indicate the highest grade possible ( where the best looking specimen gets picked) of a mineralized zone. This sample procedure should not be used to compute tonnage, or as a basis of funding operating plans.

Pan Samples

This form of grab sample most often is used in evaluating placer deposits. It can be of value too, for hard rock reconnaissance purposes. The problem with the method is often the total volume of material sampled is not known, or presented in the findings. A standard should be used to measure the source material, as a 1/2 cubic foot bucket, etc., before screening and concentrating begin.

When calculating the value per yard of a placer you must know the concentration ratio to arrive an accurate evaluation.