Ruling out all the other elements and ending up with gold
Assessing all the elements on how suitable they would be for currency, BBC's Justin Rowlatt surveys the periodic table of elements and eliminates each one eventually ending up with gold:
"Some elements are pretty easy to dismiss," [says Andrea Sella], gesturing to the right-hand side of the table.
"Here you've got the noble gases and the halogens. A gas is never going to be much good as a currency. It isn't really going to be practical to carry around little phials of gas is it?
Then there's the group called "rare earths", most of which are actually less rare than gold.
Unfortunately, they are chemically hard to distinguish from each other, so you would never know what you had in your pocket.