> So why is gold a commodity and silver the currency? People don’t want to spend the more valuable but hoard it.
Just had a simillar statement in Ketubot ~ 70: when a kalah brings cash int the family, it is added as 150% of the value as the husband will use the money to invest [it is not ribis as it is a present, not a loan]. This works for silver, but gold may not qualify for a 50% mark up because it is usually not used for transactions, but only as savings.