Gold properties, economics and resources

Gold is one of the few metals that can be mined both in artisanal workcamps and in factories processing thousands of tons of ore a day from mining operations. Of course, most of the world's production comes from mines. Gold is a rare metal, as the upper part of the lithosphere contains 0.005 ppm Au.

In its natural state, gold is found in metallic form, either pure or in alloys, generally with silver and tellurium. It is widely dispersed, and gold-bearing ores contain only very small quantities.

Its physical properties (ductility, malleability, high electrical and thermal conductivities), combined with its chemical stability and rarity, are of equal interest to industrial applications, fine crafts and financial assets. Consumption is growing, and so is primary and secondary gold production, by both large-scale producers and numerous smaller-scale companies. Cyanide is used to dissolve gold, but there are also a very limited number of other leachants that are difficult to use industrially.

Deposits come from a wide variety of sources. For some of them, the ore is difficult to leach, which means that extractive metallurgy, simple in principle, is often complex in its industrial application.