Definition: A proof coin is a coin struck using a special, high-quality minting process, and made especially for collectors. Modern proof coins often have mirror-like fields and frosted devices, although proof coins struck prior to the mid twentieth century are often distinguished only by their high quality surfaces. In all cases, the term proof always refers to a type of coin, or the way it was struck, and not to a coin's grade.
See Also: Reverse Proof Coins
See Also: Reverse Proof Coins
Examples:
You should never see proof coins in circulation, because they are made for collectors, and sold by the mint for more than face value.