Coin Errors (Part 2) - Die Errors

Coin dies are the metal tools used to strike coins and create the design on the surface. Errors can occur during the creation or use of these dies, leading to unique and sometimes valuable coins.

Now let us look at some coin errors which pertain to coin dies.

Brockage

Brockage occurs when a mirror image of a coin is struck on a blank. After a struck coin fails to eject, a new blank is fed between the struck coin and the hammer die. The hammer die strikes the second blank leaving its image on one side while pressing the blank against the previously stuck coin which sinks its image into opposite side.

Cud (Die Break)
When a significant part of the edge of the die deteriorates and falls off. The coins struck with this die exhibit a raised blank area on that part of the design. Sometimes called "major die break".

Die Clash/Ghost Error
When the upper die moves downwards to strike a coin when no coin blank is there in between, both the dies strike each other. At this high pressure of the strike, some designs of the obverse die are left on the reverse die in relief and some designs of the reverse die are left on the obverse die in relief. When any fresh blank is minted by those dies, an incused image of some text or design of the obverse die is found on the reverse side of the coin and vice versa also occurs. This type of error is called Die clash error / Ghosting error.

Die Crack

During the minting process, there are instances where a die may develop cracks. These cracks can result in the production of coins known as die crack error coins. Such coins bear the imprint of the cracked die, showcasing either a single crack or multiple cracks.

Edge and Rim Error

Planchet is surrounded by collars when struck to prevent the planchet from flattening and spreading. Edge and rim errors occur when collars are either out of position or are deteriorated. A wire rim occurs when excessive pressure squeezes out metal between the collar and the edge of the die producing an extremely high thin rim. A partial collar occurs when an out-of-position collar leaves a line around the coin which is visible when looking at its edge. A partial collar is sometimes called a railroad rim when a reeded edge coin is involved as the line resembles a rail and the reeds resemble railroad ties.

Filled Die
Filled die or grease filled die errors are actually very common and occur more frequently than you might expect. These errors occur when part of a coin’s design is obscured by grease or other foreign matter on the die’s surface. The rest of the coin strikes up, but a selected section does not.

 
Mule
A mismatched set of dies that struck a coin. Mule errors can be two different designs of the same series of coin, or of a difference series of coin matched together. It can even be a foreign coin die matched with a domestic coin die.

Wrong Collar

A reeded edge is produced by a reeded or grooved collar; the reeding on a coin is created at the same instant the piece is struck by a pair of dies. When struck, metal of the blank fills every cavity of both obverse and reverse die, it also expands between the dies up against the reeded collar filling every indentation and forming the knurls and flutes. This error occurs when wrong collar is used. e.g., plain collar is used instead of reeded collar or vice versa.