Gold as money

Gold Money - buy gold at auThe first stage in the development of money was the adoption of a system whereby items which had an inherent value were exchanged in return of good or services, for example metals like, or livestock or food grains.

Trading using these items was acceptable to most people because the items were useful and as such had value. 
The introduction of metal coins as currency rather than usable objects was a major evolutionary step.  Although, gold in the coins would have had a use value of their own, they began to be accepted because of the symbolic value and facilitated a standard measure for the exchange of goods and services.