Assume, aliens including the Anunaki, pushed humans to mine gold so the Anunaki could accumulate it for wealth. Maybe they knew wealth would be a way to buy human labor so they began accumulation immediately. (hivelink)
It is possible, the alien civilization that cohabitates in or around earth uses gold as a form of wealth and money still to this day. They may hoard it as well as using it to control human labor.
(hivelink)no youtube