Precious metals are something we all have in some form of shape.
I can't think of people around me who don't have some Gold or Silver jewelry. People don't directly relate that to money, but it obviously has weight to it, and when it has weight to it there is scrap value at the very minimum. The only thing is that in some cases people are emotionally attached to their jewelry pieces, but I think in cases of necessity, they'll be used as money.
In the end, it will all come down to what people find convenient and are used to use as money, which is cash. Governments have however started to slowly take the larger bill nominations out of circulation, which I expect to conintue until we are left with the most commonly used smaller nominations.