“Can we compare platinum, silver and gold? Or is it necessary for the metal to be useless industrially to be considered valid money in your universe?”

in my universe human beings have been using gold as a store of value for thousands of years

silver has the most history as a circulating currency

platinum is used in catalytic converters isn’t it? or is that palladium? aren’t they interchangeable?

so, we have
1) a store of value
2) a circulating currency
3) a catalyst for chemical processes

I’m not sure how to compare these three items – your analysis skills are far superior to mine, Eugene