Wednesday, November 25, 2015

Proof Coins - What are they ?

Uncirculated Coin
Uncirculated means a coin has not had any wear, such as the wear a coin might experience when it is used in commerce. Handling a coin, as well as improperly storing a coin, can result in wear on the surface of the coin.  This wear, even if very minor, will cause a coin to no longer grade uncirculated. 

When coins are minted they often bump into each other and receive small nicks and abrasion marks during the production process. These marks also occur as coins are transported in large canvas bags.  These marks, sometimes called "bag marks", are more noticeable on larger coins.

An uncirculated coin may show tarnish, toning, spotting, or discoloration and still remain in uncirculated condition.  Experts recommend you "never clean a tarnished coin", because most cleaning will cause wear on a coin, and thus lower its grade.

 

Proof Coin
A newly minted proof coin is also Un-circulated, however it is the way it is made that causes a difference in appearance and qualifies it as a "proof".  To understand this, let's look at how coins are made.  Coins are produced when two dies strike a blank piece of metal with tremendous force. One die is engraved with the front (obverse) design for the coin.  The other die has the back (reverse) coin design on it. 

By treating the die in a special way, the coins it produces have a different appearance.  Modern technology allows the high points on the coin design to be acid treated (on the die).  The background (field) design of the coin die is polished, resulting in a mirror-like look on the coin it strikes. This gives the finished coin a frosted look (frosting) on the raise parts of the design, with a mirror like finish on the background. This contrasting finish is often called "cameo". 

Not only are proofs made using specially treated dies, each coin is struck two or more times by the coin die. By striking it more than once the metal is forced into all the crevices of the die, thereby giving a very fine detail to the image on the coin.  This fine detail does not appear on some non-proof coins.   


Cameo Effect
The cameo effect on a proof coin is produced by the field having a mirror-like surface and the coin's devices having a frosted surface. If there is a dramatic contrast between the field and the devices, this is referred to as ultra/deep cameo.