As I already said, you get them through out the entire game. Even sassan sell recipes. Check out on the items tab of merchants, as some merchants sell more than a type of items. You can easily make hundreds of potions following the the steps I listed above.
If you really low on gold, just sell out all unused junk, and obtain as many gold as you can. You can even sell out those gems you collect so far but just dont sell malachite gem. Malachite ore is ok to sell. Then fully equip you gem runner and send him out to collect gems which could fetch high price. Then you can start building up your gold by selling those gem. Gem like sapphire or diamond can fetch some ok price, but which fetch the highest price, you will need to find it out on your own. Gold is never a problem in this game, you just need to know the way to earn it fast and easy.
