Essentially state and corrosion resistant, gold dissolution is not easily obtained by just any acid. Use an oxidant like manganese dioxide, nitric acid, oxygen, ferric ions or cupric ions and you will dissolve gold. The formation of Aqua Regia by nitric and hydrochloric acids will break down gold and make it go into solution.
In the presence of an oxidizing agent in an aqueous solution, gold dissolves to form another compound.
This chemistry demo video shows pure gold dissolving affect contact with Aqua Regia (hydrochloric acid + nitric acid). We’d be doing this with electronic scrap or actual gold concentrate from panning of flotation instead of coins obviously.
Cyanide dissolution is the best known way of gold extraction from ores. NaCN applied with oxygen (to oxidize). Gold oxidizes to form a compound with Potassium and Sodium. Oxygen alone with not affect gold.
At ambient temperature, halogens, such as bromine, are capable of exothermically dissolve gold.