I’ve got a few Goldbacks in various denominations. They’re basically paper-like money with a measured amount of gold foil in them depending on the denomination.
They do have a melt value based on the content, and the 50 dollar Goldback has 50 times the amount of gold in it as the 1 dollar unit.
I’m not sure if they’ll satisfy the “small denomination” issue with gold, but they have value and they’re kind of cool. Cool has a value, until you try to spend it.