Except that in practice, weights of gold are not used as a medium of exchange in almost every market in the world. Gold may be used as a store of value, but so

Except that in practice, weights of gold are not used as a medium of exchange in almost every market in the world. Gold may be used as a store of value, but so can land, buildings, collector's items, etc. One of the defining characteristics of currency is its use as a medium of exchange in a market.