The mechanics of extracting diamonds is baffling. Hell, even gold. Cutoff grades (where it is no longer feasible to mine economically) for gold is about 2.5 grams per tonne of overburden... that's a fucking metric shitpile of waste rock, some of which is ML/ARD (Metal leaching or acid generating).

I find the whole thing fascinating, and mining can be done responsibly, but it is not an easy thing in general