Gold
Gold is the synonym of money in the human psyche and has long been used as currency coins by the kingdoms of the yesteryears. It was only in the twentieth century that the governments started using cheaper metals for minting coins, though it was mandatory for them to keep stocks of this metal equivalent in value to the total currency in circulation.
No more now! The metal-stock standard got ended on August 15, 1971 and the currency turned 'fiat' with a power to come under circulation as much as any government deemed fit. But the more the currency goes under circulation the higher go the prices of this most wanted precious metal on earth! Its coins are now minted not for circulation but for collecting and investment that gives them a numismatic value as such.
I-Ching Coin
