PART V. Planchet Errors:

Lamination:

Lamination Fold-over Before Strike

Definition: A lamination error occurs when metal flakes off the surface of a coin or planchet.  It is generally believed that the flaking, peeling, and cracking is due to impurities in the alloy which causes metal to separate along horizontal planes of weakness.

The image above shows a 1964(P) Lincoln cent with a semi-lunar (half-moon shaped) lamination flap that lifted up from the edge of the coin and folded over onto what would eventually become the obverse face of the coin.

PART V. Planchet Errors:

Lamination:

Lamination loss after strike:

The 1958-D Washington quarter pictured above shows two areas where flakes spalled off the coin after the strike (indicated by black arrows).

PART V. Planchet Errors:

Lamination Errors:

Lamination on Clad Coins

Definition: A lamination error occurs when metal flakes off the surface of a coin or planchet.  It is generally believed that the flaking, peeling, and cracking is due to impurities in the alloy which causes metal to separate along horizontal planes of weakness.

A small section of metal on this 2002P Indiana Statehood quarter has peeled away and detached itself from the coin’s surface. Another area of delaminating metal – still attached – can be seen to the left of the area with the missing surface metal (indicated by white arrows).

PART X. Wastebasket / Composite Categories:

Longacre’s Doubling

While Longacre’s doubling is most associated with the Indian Head Cent. It is also found on the Seated Liberty denominations and other coins of that era.

There are two theories for Longacre’s doubling. The first, which is most popular, is that the master die was placed into the die steel to form the master die. To add details to the die, the engraver would then shave the sides of the punch used to add design elements, leaving a lip on that punch’s sides. The engraver would then conduct an extra hard hit to the punch leaving the shaved sides effects into the die. The effect would eventually wear off as the master die did age, which is why not all coins from a particular working die would have the Longacre’s doubling.

This is the second scenario. After adding the design elements to the master die, the engraver would move the punch slightly and tap it again. This would produce a ‘lip’ on the die, and the effect would make the metal flow into the punched in design elements more readily. In theory, this would also have prolonged the die’s life.

The image below shows Longeracre’s doubling on the word UNITED on an 1883 Indian Head Cent.

While the subject and study of abnormal reeding has been around for two or more decades, this sub category focuses on a coin of recent vintage, a 2008-P New Mexico state quarter. First, however, a brief history of reeding variants.

One of the best known examples is the “infrequently reeded” 1921 Morgan dollar. A rather extensive discussion of this variant can be found on pages 113-144 of Frank Spadone’s “Major Variety and Oddity Guide to United States Coins” (8th edition). Spadone notes that there are only 154 reeds versus the normal 188 reeds found on other silver dollars produced in 1921. He further observes that the grooves between the reeds are simple slots rather than the more elaborately defined notches seen in other dollars. He suggests it represents a first attempt at fabricating a collar for a denomination that hadn’t been minted for 17 years.

A very uncommon cause of abnormal reeding is collar damage or improper machining. Both Arnold Margolis and Alan Herbert report the use of a broach to create the ridged working face of the collar. A broach is a cylindrical tool with longitudinal ridges that is hammered or driven into a smooth, unfinished collar to create the ridged working face. A worn or damaged broach, or the improper penetration of broach, can theoretically produce abnormal reeding. It’s quite possible that other techniques are periodically used to create the ridged working face. It would be a simple matter to cut evenly-spaced grooves into the working face with a machine tool.

This rather roundabout introduction leads us to the focus of our entry – a 2008-P New Mexico quarter with abnormal reeding. The reeding on this quarter takes the form of low, thin ridges separated by broad, flat valleys. A normal quarter shows taller, wider ridges separated by deeper, V-shaped valleys. The ridges on the working face of the collar were ground off almost to their bases.

An essentially identical error is known on a 1964-D quarter.

Below is a 2008-P New Mexico quarter. The left image displays normal reeding. The right image displays abnormal reeding. Center image is a comparison edge view of both the normal and abnormal reeding.

http://www.coinworld.com/articles/a-second-case-of-abnormal-reeding-on-a-state

PART VI. Striking Errors:

Machine Doubling

Definition: This form of doubling typically results from vibration or instability affecting the die, die assembly, or press frame.  It has also occasionally been blamed on a coin sticking to the anvil die during ejection (“ejection doubling”).

Machine doubling has many synonyms: mechanical doubling, machine doubling damage, machine damage doubling, ejection doubling, shift doubling, and strike doubling.

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There are three basic forms of machine doubling:

Push doubling:  Push doubling occurs when a die bounces off the surface of the coin, shifts position, and lands lightly in a different spot.  A diagnostic feature is marginal shelving at the edges of design elements.  Interior features often show rounded doubling that is easily mistaken for the effects of a double strike or a doubled die.  Push doubling can occur on either face, although its most dramatic expressions tend to appear on the face struck by the hammer die.  Cases of push doubling can involve up to three closely-spaced sets of accessory design elements.  Push doubling can occur on both faces simultaneously and often in different directions.  Up to three different doubling directions can be represented on a single face.

Slide doubling:  In this form of doubling, a die drags itself through the newly-struck design, smearing the features.  Strong cases of slide doubling are always restricted to the face struck by the hammer die.  After reaching the lowest point of its downstroke, the hammer die shifts to one side without bouncing.  As it drags itself across the newly-struck design, it piles coin metal into a series of ridges.  Weak cases of slide doubling found on the reverse face have previously been assigned to “ejection doubling”, but there is no way to prove that this is actually what happened.

Rim-restricted design duplication: This rare form of doubling has to date only been detected on Presidential dollars (Washington to Madison), 1994 cents (several die pairs), a 2004 cent, and certain quarters and dimes where the peripheral letters hug a very narrow design rim.  It always occurs on the face struck by the hammer die.  After reaching the lowest point of its downstroke, the hammer die bounces up, shifts to one side, and lands lightly on the design rim, leaving a set of raised design elements.  It is also sometimes referred to as “one-sided, rim-restricted design duplication”.

The images below show “Push” machine doubling.

Part V: Planchet Errors:

Wrong planchet and off-metal errors: 

Struck on larger planchet or coin, Malaysian

“assisted errors” 2005-2007

Definition: Assisted errors are undoubtedly a major headache for mint management teams. Simply put, these errors are created by enterprising mint employees and smuggled out of the facility. Despite the intentional nature of these errors, they are highly sought after and quite collectible.

The Malaysian mint accounts for a great variety of assisted errors during the years 2005 to 2007.

A 2005 Malaysian 10 sen struck on larger 20 sen planchet.

A 2006 Malaysian 20 sen struck on larger 50 sen planchet.

Same denomination, different year. A 2005 die-struck Malaysian 50 sen over-struck by 2007 50 sen dies.

Double denomination. Die-struck Malaysian 50 sen over-struck by 20 sen dies.

A 2005 Malaysian 10 sen obverse die muled with 1 sen reverse die. A mis-match of obverse and reverse dies of different denominations.

Flip-over, triple-strike with three full dates on a Malaysian 10 sen coin. Given the near perfect symmetry of this triple-strike and three full dates, (one on each of the three separate strikes), it would seem to have required some help. Likely, it is an assisted error.

Part I. Die Subtypes:

Mid-year Design Modification: 

Small Date/Large Date Varieties

SMALL DATE                                                                                LARGE DATE

Again, note the change in position of TRUST from the large date to the small date. The small date, produced later in the year, shows a wider gap between letters and rim.”

SMALL DATE                                                                                          LARGE DATE

PART V. Planchet Errors:

Bonding / Bonding Mill Errors:

Missing Clad Layer:

Partial:

After Strike

Definition: A portion of the clad layer separates from the coin after the strike.  Exposed design elements are
characteristically mushy.  Loss of the clad layer is due to a failure for this portion of the clad layer to fuse with
the core in the bonding mill.  Inadequate cleaning of the core and clad strip may be responsible.

This 1972-S Proof Eisenhower dollar had part of the clad layer (80% silver, 20% copper) on the reverse face split off after it was struck.

Images are courtesy of Heritage Auctions.

PART V. Planchet Errors:

Annealing Errors:

Improper Annealing:

Definition: For decades error collectors have puzzled over copper-nickel and Cu-Ni clad coins struck on planchets with a layer of copper on the surface. In times past, these errors were called “copper wash” and “sintered plating” errors. The 1962 nickel shown below is a typical example. It has a thick layer of peeling copper on the right side of the obverse face. The rest of the obverse face and all of the reverse face is black. Copper, red, black, brown, and gray are colors typically found in these errors. Coverage can be complete or incomplete. The copper can range from a slight tinge to a thick coating.

In recent years, eyewitness testimony has convincingly pointed to annealing as the specific step in the planchet preparation responsible for the surface copper. In light of this testimony, these errors are now generally labeled “improper annealing” errors by the major grading services.

In 2010 Mike Diamond contacted US Mint officials with convincing evidence which in the end supported his hypothesis that copper and nickel atoms in the 75% Cu / 25% Ni alloy were migrating and segregating themselves into layers of relative purity. In response to an inquiry first made to Tom Jurkowsky, the Mint’s Director of Public Affairs, an answer came henceforth. Michael White, a spokesman for the Office of Public Affairs, consulted with the Mint’s technical staff who reported a mechanism very similar to the first scenario Mike Diamond laid out. The atoms are migrating to the surface and rearranging themselves into uniform layers. The proximate cause, according to Mr. White, is prolonged exposure to heat, a failure to maintain an oxygen-depleted atmosphere in the annealing oven, or a combination of both. Here is Mr. White’s verbatim explanation: