>What's your estimate

Good question, I would say your guess is as good as mine, but looks like you have recent statistics !

Thanks for the information, it does look like realistic figures about as accurate as you can get.

I just accept that as much as possible gold has always been hoarded much more strongly than silver amounts having the same values at the time.

Enough to regard silver as a medium of exchange compared to gold as a store of value.

Gold is so tightly hoarded that I expect that there is more than one accumulation established centuries ago, that originally consisted entirely of ancient gold which is comingled with material from the 20th century and maybe newer by now.

It's also possible that before any human value was established for gold in prehistoric times, there might just have been untold megatons within reach as low-hanging fruit without need to do very much "mining" at all.

Of course cave men had no formal education but they were sapiens just like us and had plenty of progressive generations over thousands of years to shrewdly recognize the advantage of not telling anybody about "untold" amounts of anything when it's regarded as valuable. At least some of them anyway :)

And they sure had orders of magnitude more time to pursue economic interests and accumulate wealth before recorded history than there has been since then, no telling what they were keeping off the books when there weren't any books yet !

Edit: Not my downvote! Where did that come from? Corrective upvote now placed.