RE: Bismuth, Rubidium, Tellurium
There are elements, called 'pathfinder elements', which, although not economic in themselves, can be used in indicating the potential of certain rocks to contain ore minerals. For example, enriched antimony and/or arsenic values can be used to indicate that an alteration zone has gold potential. High lead and silver may indicate the presence of certain types of gold deposits. A high content of fluorine may indicate that tin mineralization is present. In many cases, the presence of these more reactive, chemically mobile elements associated with gold present a larger, more readily identifiable prospecting target.
Bismuth and Tellurium are pathfinder geochemical elements associated with gold mineralization, and may be a reflection of more concentrated precious metals mineralization at depth. The use of geochemical mapping these multi-element halos (such as As, Bi, Sb, Te and Se) have proved to be effective in defining gold deposits.
The Au-Bi-Te-S assemblage represents an epithermal-style mineralization overprint. The best-known and most common style of epithermal deposit are low-sulfidation gold silver deposits in calc-alkaline volcanics.
Most analytical laboratories offer either single element determinations or packages that include a number of elements. The latter normally do not include gold, which must be analyzed separately at an extra cost.