The gold and silver coin value is defined by the government , not by the gold itself . After all , it is cash alike so that it is non-sense .
In the very past , gold coin value is defined by the gold value. Gold is regarded as important production material .
That's not completely true.The British Britannia has a value of £100 as a coin for legal tender, but the one off price from the Royal Mint is £986.04 today. The Shanghai gold exchange is quoting prices for physical gold.