The other part of the definition is that it can be easily bought and sold on an exchange. I think if there were an exchange for physical gold then it would be considered a security.
Exchange-traded commodity futures (including those for physical delivery of 100 troy ounces of gold) have existed for a long time and are regulated by the CFTC.
> I think if there were an exchange for physical gold then it would be considered a security.
I don't think that if you were to make an exchange that made it easy to trade physical gold (rather than deriviatives) the SEC would suddenly determine that gold was a security.