Given its value perhaps the most surprising thing about gold is how widely distributed it is; this precious metal has been found in most nations and exists in every ocean. It was probably utilised for jewellery and coins by our ancestors because of its wide geographic availability and because it was soft enough to be easily worked and did not rust. Inevitably obtaining high grade gold from mountain stream beds and near-surface ores being fairly simple has insured that such sources are now all but so depleted as to be commercially uneconomic. Large sources today are relatively high cost operations at some extraordinary depths below the planet’s surface where ores containing twenty grams of gold per metric ton are considered rich.
Recovery from seawater has not proved economic to date.
It is often said that all the gold ever mined would not fill a couple of Olympic sized swimming pools which may or may not be the case but it is worth noting that one cubic metre of pure gold weighs more the thirteen tons.