I don't think that gold and silver are money any more than Titanium and osmium are money. They are shiny metals extracted from dirt which people decided to use for money.
Printed paper isn't money either unless people decide to use it for that reason.
For many years, including recently, you could buy Belize gold coins in denominations up to $100, but they didn't circulate because you could sell the metal for more than the coins, same reason folks melted down nearly every silver coin circulating in the US.
At one time they thought copper pennies would face the same fate during the copper shortage.