In the coin collecting world, mistakes are a valuable thing. It’s rare, but coins with major errors will sometimes slip through the detailed screening process of the Canadian and American mints. These coins can be extremely valuable due to their rarity and the story they tell. Error coins are both unusual and interesting. The following are examples of common coin errors:
Type II Blank
Blank planchets are blank metal discs that would normally contain a struck image. These planchets are punched out from a large strip and are fed through a machine which rolls the outer edge created a raised edge. Occasionally, planchets will miss the stamping machine and will be included with the other coins and sent for distribution.
During the coin striking process, blank planchets are automatically fed into a coin press. Coins are fed in a way to produce a perfectly centred image on the disc. If a planchet does not line up properly the stamp will be off-centred. This will cause some of the planchet to be blank and the design will extend off the edge of the coin.
Sometimes the collar die (the circular die surrounding the lower die) malefactions. The collar die typically applies to the edge of the coin and flows to the confines of the die. When the collar is prevented from working properly during the striking process, it can rest below the surface of the anvil die. The coin will appear normal at the centre, but will larger diameter than a typical coin. This will cause the design to be distorted as it nears the periphery.
The blanking process can cause clipped planchets, this happens when metal discs are punched out from metal sheets. Sometimes a misfeed happens and the metal strip is not inserted into blanking machine far enough. When this happens, the punches will strike an area that overlaps the hole left by an earlier strike. This will cause the blank to have a missing piece.
Minting facilities are responsible for producing multiple coins, this makes it possible for a coin to be struck with the wrong planchet. The mint has processes to ensure that planchets are not mixed, but it does occasionally happen. These error coins will vary greatly, coins may simply be the wrong size, or can have the wrong nation’s stamp.
Brockage coins happen when a struck coin is not ejected from the collar properly and it impresses onto another blank that hasn’t been struck. This will cause a raised design on one side of the coin and the incuse design from the coin that sat underneath it on the other side.
Die clash happens when the coin dies come together with no planchet in between them, this causes an imprint of each die on the opposing die. The die’s impression is transferred to any stuck coins, this results in a die clash error.