We all know that gold has industrial uses. But those won't appear for thousands of years. Mentioning that you can use gold in integrated circuits does nothing to explain gold in the Stone Age.
Several others come to mind.
If it's just the pretty, shiny stuff that makes it valuable, then gold will always have some value (bar nuclear synthesis and Star Trek replicators).
If it's scarcity, then there's market manipulation and alternative artificial currency a la Bitcoin.