Coins were money. Gold was just one of the materials they were made from. There also was copper, silver, and others. Raw gold alone was somewhat useful, but AFA

Coins were money. Gold was just one of the materials they were made from. There also was copper, silver, and others. Raw gold alone was somewhat useful, but AFAIK usually not as valuable as local gold-coins. Usually trading something golden meant accepting some loss, like today.