Tag Archives: coin die

Proof coins vs Uncirculated coins

As a coin collector, it is important to know the difference between uncirculated and proof coins. As the name suggests, uncirculated coins are just that – uncirculated. They are of the same quality as circulated coins. The only difference being they have never been circulated in the market publicly. They may be packed in a sealed mint case and provided with a certificate. If preserved correctly, there should not be any visible scratches or marks on an uncirculated coin.

Proof coins on the other hand are of much higher quality than an uncirculated coins. They are specially minted to be a collector’s item and are never circulated in the market. Originally proof coins were used as a specimen coins. Before minting a new coin, few proof sets were prepared for approval by the King or the government. Later these sets were auctioned or sold off to collectors. About 200 years ago, these sets started attracting more and more attention. As a results many mints started minting proof sets for collectors.

In order to understand the difference between proof coins and uncirculated coins, it is important to know the process of coin minting. Coins are minted using a die that is struck on a metal base (usually round). Generally two dies strike a coin base on two faces (front face- obverse and back face- reverse).

A proof coin’s die is treated with special chemicals. The high points in the die are treated with acids where as the background (base) of the die is polished to give it a mirror like look. This gives a mirror finish to the proof coin in the base and a matt finish to the raise part of the coin face. Also proof coins are generally struck twice or more times to make sure that even the smallest elements of the design are clearly visible. Generally Proof coins production is manually handled i.e. they are fed into the machine for strike and then removed from the machine manually. Each proof coin is manually inspected before being packed. This results in a 99% flawless coin.

Although it is natural to assume that proof coins are more expensive compared to uncirculated coins, it may not be the case all the time. Proof coins also have a special mint marks to suggest they are proof coins.