I have been searching also, and have not found a specific provision that requires gold as national currency. For that, I am surprised. And so, I need to see how and why I had that belief.
In the meantime, it’s clear that the section you quote requires the states to do something different from what they are now doing.
Many people see the section that mentions gold and silver, but forget the part that mentions states. The founders didn't want the states to print their own paper money.
In the meantime, it’s clear that the section you quote requires the states to do something different from what they are now doing.
The Federal government made FRNs legal tender, the states don't have to do anything differently.