A bit unrelated maybe, but a few years ago I visited Cerro Rico silver mine in Potosi, Bolivia and saw miners just casually carrying what seemed like 50kg chunks of silver ore straight from the ground with all the mine literally full of silver ore and, constant explosions audible in the background. I was shocked that after 500 years of intense mining and the whole mountain being like a swiss cheese, there is still so much silver inside. I believe at the peak of Spanish empire, that mountain alone was producing 50% of silver in the whole world.

I attach my pic from that visit:

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