The combination of commodity and currency qualities of gold is its main advantage, which allows using this precious metal as a universal means of payment for all market participants. The gold standard a monetary system in which the basic unit of account is a certain standardized amount of gold. One troy ounce of gold is taken as the base of the gold standard, equal to 31.1 g of gold (investment gold). The price of invoice or the price of the contract is fixed not in currency, but in grams-kilograms or ounces of gold.