For all the gold mines springing up around the world to chase record prices, the golden era of mining has clearly passed.
One hundred years ago you could find around 20 grams of gold per tonne of ore at mines in Australia, Brazil, Canada and South Africa. U.S. ore grade peaked around 12 g/t.
Nowadays there are less than 5 grams per tonne in these top mining countries.
From a new UN report on resource depletion: