Even today with heavy machinery mining is difficult work. How did ancient societies i.e. Greek and Roman locate and harvest mineral?
A while ago, I wrote about the mining techniques of the Old Copper Complex that lived around Lake Superior 6000 - 3000 years ago. If you have any follow-up questions, feel free to ask them here.
The thread also has a great post by /u/400-Rabbits about Mesoamerican techniques, so be sure to check that out as well.
Hi! There's always room for more information about other cultures, but FYI, there's a section on this in the FAQ* where you can catch up with previous responses. (If you follow the links, you'll also run into the post linked by /u/Reedstilt)
*see the link on the sidebar or the wiki tab