Part II. Die Varieties:

Doubled Dies:

Class III (Design Hub Doubling):

1943 over 1942-P Jefferson Nickel 

This Class III doubled die occurred when a Jefferson nickel working die was first hubbed with a 1942 working hub and then hubbed again with a 1943 working hub. The P-mintmark was then later applied to this die.

The image below shows part of numeral 2 underneath numeral 3.

Images courtesy of Jim Kohl.

Such errors are sometimes incorrectly referred to as “overdates“.  An overdate occurs when two different digits (or
sets of digits) are punched into a working die.  Such errors ceased to be a possibility after 1908.

PART II. Die Varieties:

Overmintmark (OMM)

This 1938 D Buffalo nickel has a D mintmark over an S mintmark.

PART VI. Striking Errors:

Multiple Strikes:

Numerous Closely-spaced Strikes

Definition: This error occurs when a newly-struck coin fails to properly eject from the striking chamber and is struck several more times by the same die pair. A multi-struck error of this nature can occur inside or outside of the collar.

This 2000P Sacagawea dollar coin was struck 6 times. The first strike appeared to be normal, while the remaining five strikes were delivered off-center.  The coin moved slightly between each off-center strike.

Images are courtesy of Heritage Auctions.

PART IV. Die Errors:

Die Cracks:

Shattered Die

Definition: A “shattered die” features numerous intersecting die cracks.  Along with the profusion of die cracks, a shattered die can also incorporate other forms of brittle fracture such as die breaks and retained die breaks.

A shattered die often indicates a terminal die state, i.e., a die just short of catastrophic failure.  A series of coins struck by a shattered die can often be arranged in a progression of increasing severity.

The shattered die shown below has extensive evidence of brittle fracture. Many types of brittle fracture may be represented, e.g., die breaks, retained die breaks, die cracks, a split die, etc. The die may or may not be approaching catastrophic failure (see Catastrophic Die Failure). Not surprisingly, a series of coins struck by a shattered die can often be arranged in a progression of increasing severity.

Note: Two separate specimens are shown below.

The 1985 India 25 paise shown below Features a large retained cud, a small retained interior die break, and numerous die cracks, most of them bi-level. The right side of the obverse face and the corresponding left side of the reverse face are weakly struck. This is largely due to a tilted die error (vertical misalignment) of the entire obverse face. The left side of the obverse is quite strongly struck, despite the large retained cud. This should have led to a reduction in effective striking pressure. The fact that it didn’t indicates that this part of the obverse die face was tilted down, while the opposite pole was tilted up. This tilt was most likely due to a break at the base of the die or through the shaft of the die – a break that allowed the die to tilt down strongly toward one pole.

The 2002 Brazilian 10 centavos shown below expresses various forms of brittle fracture.  There are three cuds, one retained interior die break, and a tracery of intersecting die cracks of both the conventional and the bi-level type.

PART VI. Striking Errors:

Multiple strikes: 

In-collar/out–of-collar

Definition: Multiple strikes can occur inside the collar or outside the collar.

A 1998 Lincoln cent double struck in-collar with 90 degree rotation between strikes.

PART VI. Striking Errors:

Multiple strikes:

Flipover Double and Multi-Strikes

Definition: Most multi-strikes show the same face struck repeatedly. Coins that flip over between strikes are rarer.

The 1935 Lincoln cent shown below is an in-collar, flipover double strike.  After a normal first strike, the coin flipped over and landed back inside the collar.  It was then struck a second time.

The 2000 Lincoln cent shown below was first struck off-center.  It then  flipped over and was struck a second time
even farther off-center.  The second strike is uniface (struck against another planchet).

PART III. Die Installation Errors:

Mules: 

Two Different Denominations

Debuting in May of 2000, this slip up was destined to make history. At the time, it was the only known “mule” coin in United States history.

For those who are not professional numismatists, a mule is a pairing of two different coin designs on one coin — in this case, a State Quarter and the brand new Sacagawea dollar. Previous to the discovery specimen of this famous coin, mules were not known to exist in United States coinage, though commonly found in foreign series.

After authentication and subsequent confirmation of its existence by the United States Mint, a firestorm of controversy was set off. How could this happen? Was it intentional? The biggest debate — was it legal to own?

After near forensic inspection and an unconfirmed report by an anonymous US Mint employee, it was determined that the anomaly was produced due to the similar sizes of the “coin dies” of a State Quarter and the new Sacagawea dollar. A coin die is the part of a coin press that places the design on the coin. Ironically, this was the very reason that the previous dollar coin, the Susan B Anthony, was despised by the public.

The quarter die was placed into a press currently in production of Sacagawea dollars. The rest is history — several coins were struck before the error was discovered. Many of the coins were discovered before reaching the public and were subsequently destroyed.

Interestingly, upon closer inspection of the 10 known specimens, it’s apparent that the errors were produced at three separate times. It’s theorized that these are “copycat” errors produced by rogue US Mint employees after word spread of the first discovery. Many of the coins were discovered in Philadelphia, the home of the primary United States Mint.

While it’s been nearly a decade since the last sale of the Sacagawea Mule, it’s speculated that they could bring a whopping $250,000 at auction. 8 of the 10 known specimens have been handled by the author, Fred Weinberg of Beverly Hills.

There are now ten (10) confirmed specimens of the Sacagawea Dollar/Quarter Mule. The ten confirmed specimens
are:

Mule #1. The “Discovery” specimen, found in Mountain Home, Arkansas by Frank Wallis. Originally sold by Bowers & Merena Auction Galleries at the 2000 ANA Philadelphia Millennium Sale for $29,900. Purchased from Dwight Manley by Fred Weinberg in late June 2001 and then sold to Tommy Bolack for $67,000.  PCGS MS-66 (Die Pair #1)

Mule #2. The “eBay” specimen, sold by Delaware Valley Rare Coin Co., in Bromall Pennsylvania for $41,395 in July 2000. Purchased at the Heritage Numismatic Auctions Signature Sale held June 1, 2001 at the Long Beach Coin Expo for a then record price of $56,350, by Tommy Bolack. NGC MS-67 (Die Pair #2)

Mule #3. The “Heritage Auction” specimen, sold in the Heritage Numismatic Auction Pre-ANA Sale August 6, 2000 for $31,050. Then into a private collection, after being purchased off an eBay Auction in October 2000. Currently owned by Tommy Bolack. NGC MS-66 (Die Pair #2)

Mule #4. The “Margolis” specimen, originally from Fred Weinberg of Encino, CA. Sold by Arnold Margolis to a private collector in September 2000 for $47,500. PCGS MS-65 (Die Pair #1)

Mule #5. The “Greg Senske” specimen, found in Cape Girardeau, Missouri. This coin was discovered Sept. 2000 in change from a cashier at a cafeteria, and was in a 25-coin roll of Sacagawea $1, wrapped in a U.S. Mint designated paper wrapper. This piece is not on the market at this time. NGC MS-67 (Die Pair #3)

Mule #6. The “Fred Weinberg” specimen, discovered on the East Coast in June 2000 and sold by Fred Weinberg at the Long Beach Coin Expo October 5, 2000 for $50,000 to an anonymous collector. Purchased in May 2003 for $75,000 by Tommy Bolack. PCGS MS-66 (Die Pair #1)

Mule #7. The “Philadelphia” specimen, purchased by Tommy Bolack from Maryland Coin Exchange in early February 2001 for $48,000. MCE purchased this piece from the man who discovered it in a roll of dollars in July 2000 in Pennsylvania. NGC MS-64 (Die Pair #2)

Mule #8. The “Tommy Bolack-1” specimen, purchased in June 2001. The purchase price was not disclosed. PCGS MS-66 (Die Pair #1)

Mule #9. The “Tommy Bolack-2” specimen purchased in July 2001. The purchase price was not disclosed. PCGS MS-65 (Die Pair #1)

Mule #10. The “Treasury” specimen, first reported in August 2001 by a convenience store owner who received it in payment in his downtown Philadelphia store in summer 2000. It was taken by Treasury Dept. officials in August 2001 to verify authenticity and to examine the piece at the Philadelphia Mint. It was returned by the Treasury Department in October 2001 and subsequently purchased by Fred Weinberg, who sold it in November 2001 to Tommy Bolack for $70,000.

PART VI. Striking Errors:

Malrotation Errors:

Definition: Malrotation errors are restricted to coins with polygonal or scalloped edges.  If the points of a polygonal planchet overlap the “flats” of the collar, or if the points of a scalloped planchet overlap the “peaks” of the collar, the planchet will not fit.  If the collar is unyielding (a stiff collar error), the planchet will driven into the collar, forcing the points upward.

Part V: Planchet Errors:

Blanking and Cutting Errors:

Multiple clips and combination clips:

Definition: Two or more clips of the same type or of different types can appear on the same coin.  Any combination of curved, straight, ragged, and elliptical clips is possible.

The percentage of missing metal, or mass, on a clipped planchet is often expressed as a measurement of weight. The measurement will normally be expressed in grams or grains.

For expanded treatment concerning clip diagnostics click here.

Below is a 2001-P Jefferson nickel with a combination curved and straight clip. Image courtesy Ynes Zavala.

Shown below is a quad-clipped dime that consists of an elliptical clip (best seen on the left) and three curved clips.

1982 Mexican 1 peso coin with six curved clips. Three overlapping curved clips are situated at opposite poles. The edge shots show a nice cut-and-tear texture.

A Malaysian 20 sen struck off-center on a double curved clipped planchet.