Is there any online sources I can use to find an estimate of how much of a particular resource has ever been mined?

For example, how many kilos of a metal like gold is just floating around in the world, or how much of a rare gemstone we’ve ever found, etc. I don’t expect it to be a convenient site with a table containing everything I want to know, or incredibly complete with hundreds of types of minerals, or even the data to be very accurate.

If this is not the place to ask, I’d appreciate suggestions for other places to ask before the post is removed.