Definition of a Cud
A cud on a coin is a damaged area resembling a blob on the surface of a coin which is raised above the field, and which obliterates the device or inscription where it appears. Cuds are the result of die cracks or die breaks which have become severe, or from die chips where part of the die surface has become damaged and broken away.
Some experts in the coin error-variety hobby insist that for the blob to be called a cud, the damaged part of the die must include part of the edge of the die.
Although this is the purist definition, in common parlance you'll see the term "cud" used to describe the blob created by any die chip or serious die crack, regardless of its placement on the die or coin.
What Causes Cuds on a Coin?
As a coin die continuously strikes coins in the coining press, the tremendous pressure used to mint coins causes stress on the metal coin die. Additionally, the friction on the surface of the die from striking the planchets causes the surface of the die to deteriorate. Combine these with a variety of other factors and a coin die can become damage through normal usage.
Additionally, the metal collar that holds the planchet centered above the anvil die can sometimes move and get struck by the hammer die. If a die has been in the coining press for a while and has experienced the stresses of coining for a period of time, a piece of the die can break off. This will leave a damaged coin die that will produce a cut.
In the early years of the United States Mint coin dies were made by hand and were very expensive. Therefore, they were used in the coining press until they deteriorated or produced such low quality coins that they were no longer deemed adequate to strike coins. Therefore, many early coins have cuds on them because the mint employees were trying to extend the life of the die for as long as possible.
Modern minting processes allow coin dies to be mass-produced and are significantly cheaper than the early coin dies of the United States Mint. Therefore, at the first sign of a coin die that is showing deterioration or stress cracks, the die will be retired in a new die used in its place. This has resulted in fewer cuds appearing on modern coins.
How Much Is a Coin With a Cud Worth?
Very small cuds are not usually valuable unless they appear on Proof coins. Cuds which can be seen by the naked eye are usually worth a small premium over normal value, and some cuds have actually been cataloged and are collectible, such as those on Morgan Dollars or between the letters of LIBERTY on Wheat Cents.
Many die breaks and cuds on Morgan and Peace Dollars have been described and cataloged as VAMs.
Edited by: James Bucki