ABSTRACT
The earth’s crust contains an estimated average gold content of 0.0035 grams per metric ton or 3.5 ppb (parts per billion). Gold is found on all continents in many kinds of rock, and there is gold content in sea, surface and ground water. It occurs mainly as a native metal, alloyed with silver and other metals. It shares the basic characteristic of all ores that are mined, which is, that the discovery of a worthwhile deposit is still a largely fortuitous event only less likely to be uncovered by an isolated prospector with a metal detector or pan than by a fully equipped geophysical and chemical prospecting crew, because the latter can cover more ground faster and with less individual effort.
