A counterbrockage is a raised, normally oriented version of the design that is produced when a brockaged coin is struck into a planchet. The brockage — an incuse, mirror-image version of the design — acts like a “soft die.”
The most common type of counterbrockage found among domestic coins is one that is centered, in-collar, and depicts the obverse (hammer) die’s design on the obverse face. But counterbrockages are far more diverse than this. Previous columns have featured partial counterbrockages, several types of brockage-counterbrockage combination errors, and counterbrockages of the anvil die’s design. Shown here is a 1995-P Roosevelt dime with a partial counterbrockage of the obverse design on the obverse face.
I know of only one double-struck coin (a cent) in which the second strike left behind a partial counterbrockage superimposed over flattened first-strike elements. Such an error requires that two previously-struck coins occupy the striking chamber at the same time — one a brockaged coin and the other a conventionally-struck coin. This is certainly possible, as errors involving the simultaneous presence of three loose, previously-struck coins are known. Such crowded conditions can result from a failure of the ejection mechanism, coins bouncing around inside the press’s noise-dampening shield, or a migration of coins from an adjacent striking chamber.
Another scenario can generate a counterbrockage on the final strike, and it initially only requires the presence of one conventionally struck coin and an unstruck planchet. However, three strikes are required.
The first strike is a conventional one. The second strike involves an intrusive planchet that leaves an indent on the first coin. Flattened first-strike elements occupy the floor of the indent, as seen on the illustrated double-struck cent. At the same time, the overlying planchet is converted into an off-center coin with a brockage on one face. An undated, off-center Lincoln cent illustrates this type of error.
After the second strike, the brockaged coin shifts position but still overlaps the matching indent. The third strike drives the brockage back down into the indent, generating a counterbrockage that overlaps the flattened first-strike elements. I’ve chosen the moniker “rebound counterbrockage” to reflect the rapid, reciprocal nature of this type of counterbrockage.
A triple-struck 2005 1-rupee coin of Pakistan shows a rebound counterbrockage on the third strike. The first strike was entirely normal. The second strike was slightly off-center toward the south, with an unstruck planchet covering the lower 40 percent of the obverse face.
When the two discs were struck together, the overlying planchet generated an indent containing flattened first-strike elements that include the neck of Mohammed Jinnah and the date. The second strike also converted the intrusive planchet into an off-center coin with a brockage of the obverse design on its reverse face.
After the second strike, both the brockaged top coin and the indented bottom coin shifted position toward the south, with the brockaged coin moving a bit farther in that direction.
During the third strike, the brockage was driven back into the indent, producing a counterbrockage that overlies the flattened first-strike elements and which duplicates those elements in a slightly offset position.