Remember, if you consider money to be something that fluctuates in value with relation to other money, then it is the fiat currencies that are money more than almost anything. Yet, by this definition, gold and silver are money, as well, because they fluctuate in value with relation to each other as well as with relationship to fiat currencies.

What does NOT fluctuate in value is the number of loaves of bread you can make with 100 pounds of flour. You ALWAYS make the same number of loaves of the same kind of bread with 100 pounds of the same kind of flour using the same recipe.

You can't eat gold and silver, or fiat money. At least, not very easily.

Afghanistan has been getting around sanctions for a long time with a different kind of "currency": poppy.

 http://www.hurriyetdailynews.com/iran-buys-turkish-gold-with-money-from-gas-exports-deputy-pm-says.aspx?pageID=238&nID=35310&NewsCatID=344