Commodity market in Sumer between 4500 BC and 4000 BC. Sumerians first used clay tokens sealed in a clay vessel, then clay writing tablets to represent the amount—for example, the number of goats, to be delivered. These promises of time and date of delivery resemble futures contract. Early civilizations variously used pigs, rare seashells, or other items as commodity money. Since that time traders have sought ways to simplify and standardize trade contracts. Gold and silver markets evolved in classical civilizations. At first the precious metals were valued for their beauty and intrinsic worth and were associated with royalty. In time, they
Commodity money a legal code. Several centuries after the invention of cuneiform script, the use of writing expanded beyond debt/payment certificates and inventory lists to codified amounts of commodity money being used in contract law, such as buying property and paying legal fines. Today, the face value of specie and base-metal coins is set by government fiat, and it is only this value which must be legally accepted as payment for debt, in the jurisdiction of the government which declares the coin to be legal tender. The value of the precious metal in the coin may give it another value, but this