I found this website which details the discovery of metals. What I don't understand is how was man designing gold 6000 years ago with no heavy tools?
It also says that lead smelting began 9000 years ago. How was that possible? What did they use for furnaces.
I thought humans were still rubbing sticks together until 3000 bce
http://www.makin-metals.com/about/history-of-metals-infographic/
Gold, in comparison to other metals is very soft, so work it could be done with simply beating it and then cutting or softening it in a fire. The same with lead, its softness and lower melting point means that it's very easy to extract it from ores.