NGC recently authenticated a 2009 D Zachary Taylor Presidential $1 coin bearing the date 2010 D on its lettered edge.

NGC has certified a Zachary Taylor Presidential $1 coin that bears the date 2010 D. The Zachary Taylor coin was the fourth Presidential dollar released in 2009 and should correctly bear the date 2009, not 2010. This is the first time that the wrong date has been reported on an edge-lettered US dollar.

The date on each Presidential $1 coin appears on its edge and is applied by an edge lettering die after the obverse and reverse are struck with a blank collar. Because edge lettering is an additional and subsequent step, it has been the source of several types of novel mint error coins. Most common among these errors is partial edge lettering, which occurs when a coin gets hung up in the edge lettering machine and part of the edge lettering is not impressed. Another error is missing edge lettering; that error occurs when a coin misses the edge lettering step entirely. A third error type that has been encountered is doubled edge lettering, which is created when a coin passes through the edge lettering machine twice.

While there are many possible explanations for how this incorrect date error may have occurred, its story is seemingly revealed by the coins that accompanied it. This error coin was included in a roll of 2010 D Native American $1 Coins that were purchased using the US Mint’s Direct Ship Program. Since only this lone Zachary Taylor $1 was found in the roll, one can speculate that the same machinery was used to strike 2010 D Native American dollars after completing a run of 2009 D Zachary Taylor dollars. A coin was left behind somewhere between striking and edge lettering became mixed with Native American dollars headed for the edge lettering process, and was thus inscribed with the wrong date.

Because of where this coin was found, it does not suggest that a large run of error coins were made and, therefore, this type of error coin may remain a significant rarity. (more…)

By Ken Potter

By way of introduction, I am an error and variety coin specialist from Michigan. As a charter life member of the Combined Organizations of Numismatic Error Collectors of America (CONECA) and a founding member of the National Collector’s Association of Die Doubling (NCADD), I serve both groups independently as their official attributor of world (non-U.S.) hub doubled dies and I privately list all types of die varieties on both U.S. and other world coins in the Variety Coin Register(r). I am also a columnist for Coin World, World Coin News, Canadian Coin News, Cherrypickers’ News and several club publications.

While I plan to examine issues other than errors and varieties, most of what I plan for this column will relate to my area of expertise. Before getting started I should mention that varieties listed within the Variety Coin Register(r) (VCR) are assigned a primary VCR number and a secondary number that defines the variety type or class. This reference number will accompany the description for most varieties shown in this column. I believe the system is rather self- explanatory but if anybody desires a detailed explanation they may contact me via e-mail and request “Form#VCR”.

Another item in need of explanation is how I differentiate between errors and varieties. The lines of demarcation are not always clear and tend to vary between specialists. One area of agreement is that any mechanically misstruck coin or a coin struck on an improperly prepared planchet is an error coin. It is also a consensus that any coin displaying a deliberate change in design is considered a “die variety”. Thus a coin struck “off-center” or “struck on a damaged planchet” is considered and “error” while a coin exhibiting a change in the style of lettering, etc., is considered a deliberate “variety”.

Some specialists argue that certain “varieties” such as repunched Mint marks (RPMs) and hub doubled dies are actually “errors” because there is no intent by the Mint to prepare a “flawed” die. Others argue many RPMs and doubled dies are more appropriately defined as a “variety”; they believe they’re deliberately released and contend that many issuing authorities consider such flaws trivial and an expected byproduct of tolerances and processes in place (a stance with which I pretty much agree).

It is also known that some “overdates” were deliberately created by the Mint to extend the life of an otherwise obsolete die, while it is presumed that others were created in error. While most specialists agree, determining which dies were deliberately overdated and which were not is often an exercise in futility. Thus we cannot know for certain if we can accurately apply the term “error” to many “overdates”. (more…)

U.S. coins struck with dies of different denominations are extremely rare. Until recent years, none were known.

The most famous among those are the Sacagawea dollar reverse, paired with a statehood quarter obverse, of which ten examples are known, per Fred Weinberg.

In Heritage’s April 2006 Central States Signature, a 1999 cent with a dime reverse hammered down for $138,000, the largest prices realized for an error coin in a Heritage auction, excluding the 1944-S steel cent that sold for $373,750 in our 2008 ANA Signature.

Aside from malfeasance of a mint worker, the muled denomination error is only possible when the denominations involved are similar in diameter. A cent is 19 mm, and a dime is 17.9 mm, a difference of 1.1 mm or approximately 5%.

Given the billions of cents struck annually at the Federal mints, it was inevitable that an absent-minded worker would pair cent and dime dies.

Presumably, the mistake was discovered and the struck pieces were destroyed before dispersal, with the single exception of the present survivor.

This lustrous Gem shows the characteristics expected of a cent and dime mule. The dime side has a broad, tall rim, since metal was forced into the collar of the dime die by the wider diameter cent die opposite. As a result, the cent side has a soft strike near the rim, since metal in the vicinity flowed into the dime collar.

This coin is being offered for sale at Heritage’s 2010 FUN Auction as Lot 2383