Ugh, that last one's tough! So far I've found sites that claim it was Egypt, Sumeria, Mesopotamia, Assyria, and India. And none of them agree on when--some say it wasn't smelted by anyone 'till 3000 BC, others that it was first smelted in 7000 BC. And none say it was both smelted and mined by one group--they all claim it was only one or the other.
Thanks!
Correction...This site claims the Egyptians did both in 5000-4001 BC
http://www.happychild.org.uk/timeandspace/ But no telling if they're right.