In the days before geology, how did miners know where to dig?

by Pinejelly

Did they just have to dig where there were minerals very close to the surface? Or just dig randomly and hope to strike lucky?

Searocksandtrees

Hi, while you're waiting for answers here, you might check out the FAQ

FAQ section Science - scroll down to section Mineral Resource Extraction (sorry I can't give a direct link - am on mobile)