I have been trying to figure out this question since 2016, and I still haven’t found the answer yet, what pickaxes can mine gold. I looked up this question on google and it just said what the item is, not the pickaxes.
In my worlds, any pick can do it. Try a copper one to start with. Remember though, stronger pickaxes can mine faster.
An iron, copper, lead, and all sort of pickaxe that is made using materials that are better than wood can mine gold.