If gold would still have value, people with guns and ammo would take it. In the case of a collapse, guns, ammo, nonperishable food, and soap would be valuable, and soop could be used as currency, assuming we don’t totally sink to savagery. It can be easily divided and subdivided. As trade/barter goods, don't forget liquor, which will keep a LONG time in the bottle.
Black Powder and Alcohol