PART VI. Striking Errors:

Brockages:

Clashed Cap Strike:

Counterbrockage/Clashed Cap Strike

Definition: This is one of the eight ways in which a brockage-counterbrockage error can be generated.  In this scenario, an obverse die cap that is striking counterbrockages clashes with the reverse die when a planchet fails to be fed into the striking chamber.  The working face of the die cap picks up an incomplete set of reverse design elements while, at the same time, some of the incuse, mirror-image elements on the working face of the cap are erased.  The next planchet to be fed into the striking chamber after this event is left with a sharp, incomplete, unexpanded brockage and a scattering of counterbrockage elements.

The 19XX Lincoln cent above shows an expanded counterbrockage and an incomplete secondary brockage (first impression).  The brockage is derived from elements transferred to the working (reverse) face of the die cap during the clash.  The semicircular elevation on the right represents an indent on the working face of the die cap.  The die cap struck a planchet that was fed partway into the striking chamber.  This presumably occurred prior to the clash.

PART IV. Die Errors:

Die Deterioration / Deformation errors: 

Die Deterioration Doubling:

One of the more infamous examples of die deterioration doubling appeared in 1955 when working dies for the Lincoln cent were not replaced in a timely manner.

The doubling formed on the last digit (5) of the date and in extreme examples, the last two digits of the date (55).

The true 1955 doubled die cent neither resembles nor is related to this very common effect. However,  since it occurred in the same year as the famous doubled die cent, this common form of doubling was christened the “poor  man’s double die” and used as a space-filler for the true 1955 doubled die.  Similar doubling of the last digit can be found in Lincoln cents from 1947, 1948, and 1953.

PART IV. Die Errors:

Die Deterioration / Deformation errors: 

Die Deterioration Doubling

Definition: Die deterioration (die wear, die fatigue) sometimes produces discernible doubling of affected design elements.  We call this die deterioration doubling (DDD).  Its appearance is highly variable.  It is often raised but can sometimes be incuse.  Incuse DDD is most often seen on copper-plated zinc cents, but does occasionally appear in other issues.  Die deterioration doubling may completely surround an affected design element (like a number or letter) or may be restricted to one side.

The images below shows die deterioration doubling on a 1955 Lincoln (raised), Jefferson nickel (raised) and 1989 Lincoln (incuse).

Part IV. Die Errors:

Die Deterioration/Deformation Errors:

Die Deterioration Promoted by Trails (oblique flow

lines)

Definition: This type of die deterioration is promoted by a pre-existing condition called trails.  Trails are a form of die deformation or die damage that develops during hubbing. Metal flow lines, which are an indicator of die fatigue, are normally radial in direction. However, with the die deformed by parallel trail lines, the metal flow will follow the path of least resistance and be seen as parallel flow lines that are often obliquely oriented.

The 1997(P) Lincoln cent pictured below shows a combination of parallel die flow lines as well as trail lines. The trails seen atop the word IN have yet to be augmented by flow lines, while the closely spaced, parallel lines atop the word GOD are flow lines that have formed alongside and on top of pre-existing trails.

This situation becomes more apparent when looking at the word WE. The trail lines emerging from the top right corners of the two letters have been enhanced by metal flow.  This condition can be seen in the word TRUST as well.

The next example shows a slightly different direction in the die flow and trail lines. However, both are still parallel in direction. The images below are from a 1998(P) Lincoln cent.

The example shown below could almost pass as a replica of the 1998(P) cent pictured above. However, this example was found on a 1999(P) Lincoln cent. Once again, the deformities are all parallel to each other.

PART IV. Die Errors:

Die Damage:

Die Gouges

Definition: Die gouges occur when a foreign object is dragged across, and digs into, the die face. Such gouges will appear as raised areas on the coin’s surface.  Die gouges are easily confused with linear die dents.  The former are most easily diagnosed when there are clear longitudinal striations within the body of the die gouge.

PART IV. Die Errors:

Die deterioration/deformation errors: 

Die Subsidence (a.k.a., sunken die)

Definition: Die subsidence is a form of plastic deformation that results in a portion of the die face sinking in. The term “subsidence” is derived from geology. It means a sinking land surface. A synonym for die subsidence error is “sunken die error”. The coin itself will show a bulge on one face. The opposite face may or may not show weakness in the design. It rather depends on how deeply the die face recedes.

The appearance of die subsidence errors is highly variable. It can be local or global (affecting the entire die face). Localized forms can be compact, elongated, circular, or oblong.

Die subsidence errors are often associated with cracking. The die cracks (conventional or bi-level) can skirt or penetrate the zone of subsidence. Other errors sometimes found in association with die subsidence errors include split dies, shattered dies, interior die breaks, retained interior die breaks, and retained cuds.

The causes of die subsidence errors are conjectural. They may reflect an abnormally soft interior that results from improper heat treatment (e.g., cooling, heating, tempering, quenching). They may reflect an intrinsic flaw in the die steel or the use of the wrong type of steel. Subsurface cavities, or pockets of low-density contaminants such as slag might also contribute to the formation of a zone of subsidence.

Note: Several specimens follow

 Shown here is an Indian 25 paise with a die subsidence error in association with a split die and what might be either a cud or a retained cud.

PART V. Planchet Errors:

Double Denomination Errors:

Dual Country:

Different Year

Definition: This error occurs when a coin carrying the design of one country is struck a second time by a coinage press striking coins for another country that also happen to carry a later date.

The double denomination error shown below consists of a 1964 Kennedy half dollar design that was struck over an off-center 1963 Philippines 10 centavos.  The U.S. Mint was striking coins for the Philippines during this time period.  Unlike most dual country/dual year/double-denomination errors, there is every likelihood that this was an accidental occurrence.

PART II. Die Varieties:

Different Mintmark Styles And Sizes

Definition: This occurs when two or more different style mintmarks of the same size are used on working dies from the same mint during the same year on a denominational coin.

In the year 1944, two different style “S” mintmarks were used on the working dies of the Lincoln cent. The image to the left shows the serif mintmark, which was a carry over from the year 1943 where it was used on the 1943 Lincoln cent. The image to the right shows the ball serif “S” mintmark. The serif “S” mintmark is the more common of the two mint marks used for this year.

PART V. Planchet Errors:

Wrong Planchet:

Domestic Coin Struck on Foreign Planchet

Definition: A coin that is struck with domestic dies but on a planchet intended for foreign use.

In 1940, the U.S. Mint struck bronze 1¼ centesimos and copper-nickel 2½ centesimos for Panama. This 1941 -P Lincoln cent was struck on a 3.1 gram bronze Panama 1¼ centesimos.

Images are courtesy of Heritage Auctions.

Images courtesy of Heritage Auctions.

This 1905 Barber dime is struck on a possible Panama or Philippines five centavos planchet weighing 1 gram. The normal weight for a Barber dime is 2.5 grams.

Images courtesy of Heritage Auctions.

This 2000-P Sacagawea dollar error was struck on copper-nickel ring intended for a Ghana 100 Cedis. The 100 Cedis is a bimetallic coin with a brass center framed by a copper-nickel outer ring.  The ring almost certainly came from the Royal Canadian Mint, mixed in with a shipment of Sacagawea planchets.  During periods of peak demand, the RCM processed dollar planchets for the U.S. Mint. The diameter of the ring was close enough to the standards of a Sacagawea dollar to escape the Mint riddlers.

Images are courtesy of Heritage Auctions.