A coin is a small, flat, round piece of metal or plastic used primarily as a medium of exchange or legal tender.They are standardized in weight, and produced in large quantities at a mint in order to facilitate trade. Coins are usually metal or alloy, or sometimes made of synthetic materials. Coins made of valuable metal are stored in large quantities as bullion coins.For most of recorded history money has meant coins.
Use the price guides in some of the links below or try coin dealers, the numismatic collections of libraries etc.
China was among the first countries in the world to use money as documented by historical records and actual artifacts dating back 4,000 years.
By the time of the Shang Dynasty (16th ~ 11th century BC), sea shells (cowrie) were already circulating as a major form of currency.
Examples of modern gold collector/investor coins include the British sovereign minted by the United Kingdom, the American Gold Eagle minted by the United States, the Canadian Gold Maple Leaf minted by Canada, and the Krugerrand, minted by South Africa.
While the Eagle, Maple Leaf, and Sovereign coins have nominal (purely symbolic) face values; the Krugerrand does not.