3. Mining reserves

Gold is a fairly common metal, as many rocks contain it at very low levels, from which it is unthinkable to extract it economically. This distribution is in contrast to that of certain metals whose occurrences are rarer, but correspond to exploitable concentrations (tin, copper, for example).

The mining reserve values shown in table 5 are approximations, and are certainly incomplete, as they do not take into account easily recoverable gold and so-called "refractory" gold 9