I've meant to look into a timeline of how much gold has been mined since the beginning of history, who had it, how much came from the New World, etc.
My 1965 Britannica has some of it, I think, but I can never remember it unless I write it down.
I didn’t it expect it so much to be the specific gold sent back to Greece by Alexander as being “descended” from that gold. Alexander’s gold (Persia’s gold) would have been floating around the Greek world and significantly increased the supply. I just don’t know if there has been an analysis to determine the percentage of gold in various treasuries that came from that original source. It would be a good way to map trade routes.
The encyclopedias here date from early 1960s; at that time the figure for all the gold ever mined had hit a 50 foot cube; now the amount is closer to 80, which means that more than half of the gold ever mined has been since circa 1960.