I've been looking all over the map and can't seem to find any gold nodes. Does it drop from enemies or am I missing something?
You need Qingyan in your party (a companion who can be recruited from the Colosseum after winning enough fights and then beating the boss afterwards) and to then visit the Zehram Border Ravine and interact with the wall to locate a hidden cave with a gold node inside.
In hindsight I think I might add a few more nodes since it's pretty hard to find this, so thanks for bringing it up.