Search Results for: doubled dies
Comprehensive Error-Variety Checklist
Compiled by Mike Diamond
This checklist is my attempt to compile a comprehensive listing of all known variety and error types, subtypes, and associated effects. It is updated periodically to reflect the current state of knowledge.
While the traditional planchet-die-striking method of classification hasn’t been completely abandoned, it has been absorbed into a much more detailed and precise taxonomy. This is intended to reflect the numerous steps (and missteps) in the minting process that generate the great diversity of anomalies presented here.
Many of the categories will be familiar to veteran collectors. Others will perhaps be dimly recalled, while others will be unfamiliar. Many of the more obscure error types have been treated in detail in articles published in Errorscope. These articles are referenced next to the appropriate entry (“ES”). Other treatments can be found in Coin World (“CW”).
I have tried to restrict this checklist to basic error/variety types and subtypes. Combination errors have been kept to a minimum. Had I attempted to incorporate all conceivable two-error combinations, this would have generated almost half a million entries. That would have been both unwieldy and unnecessary.
ES=Errorscope
CW=Coin World
Part I. Die Subtypes:
Patterns and Prototypes (accidental release)
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- 1916 Winged Liberty (“Mercury”) dime patterns
- 1971-S Eisenhower dollar prototype
- 2000-P Sacagawea “Cheerios” dollar
Mid-year design modifications
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- 1796 to 1799; 13, 15 and 16 stars on the U. S. dime, half dollar and dollar
- 1853 Seated Liberty dimes and half-dimes, with and without arrows
- 1867 Shield nickel with and without rays on the reverse
- 1883 Liberty Head nickel; with and without the word CENTS
- 1909 Lincoln cent; with and without the designer’s initials (V.D.B.)
- 1913 “Buffalo” nickels; Type I and Type II
- 1917 Standing Liberty quarter, with and without exposed breast
- Small date /large date
- 1960 Lincoln cent; small and large date
- 1970 Lincoln cent; two styles of date
- 1974 Lincoln cent; small and large date
- 1982 Lincoln cent; small and large date
- 1979-P Susan B. Anthony $1 (Near Date, a.k.a. Wide Rim)
- Different placement of mintmark within the same year
- 1872 Seated Liberty Half dime
- 1875 Seated Liberty dime
- 1917 Walking Liberty half dollar
- 1942 Jefferson nickel; with and without mintmark
Conceptual design flaws (foul-up in design or in translating design to master hub or master die) (CW 11/15/21)
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- Misspellings (foreign only) (CW 1/25/16, 4/18/16)
- Chile 50 Peso, with country’s name misspelled “CHIIE”
- Brazil (Brasil) 1000 Reis, 1922, with country’s name misspelled “BBASIL”
- Croatia 1 Kuna, 1994, with bird’s name misspelled “LUSCINNIA”
- Inaccurate design
- Italy 1000 Lire with outdated map borders
- Montreal $5 Olympic Coin, 1976. Runner with two left feet
- 1828 half cent; with 12 stars
- 1832 $5.00 gold; with 12 stars
- 1817 Large Cent with 15 stars on the obverse (possibly done intentionally as a political statement)
- 1804 Draped Bust dime with 14 stars on the reverse (possibly done intentionally as a political statement)
- Misspellings (foreign only) (CW 1/25/16, 4/18/16)
Mistakes during design modification
-
- 2007 Mexico 10 pesos with reversed dentils
- 2008 Chile 50 pesos with country spelled “CHIIE”
Unauthorized strikes and unauthorized issues (CW 1/20/14)
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- 1913 Liberty Head nickel
- 1954 Mexico 5 centavos (small size)
Part II. Die Varieties:
Reduction lathe doubling (master hub doubling)
Master die doubling (master die with a doubled die variety) (CW 7/27/20)
Broken hub (chipped hub) (CW 12/23/13, 5/21/18)
Hubbed-in debris (CW 5/27/13, 1/17/22)
Damaged punch
Longacre doubling (probably impressions of punch shoulders)
Doubled dies (incl. tripled dies, etc)
-
- Rotated hub doubling (Class I) (CW 8/8/16)
- 1872 Seated Liberty dime with 175 degree rotation
(ES July/August 2003; CW 2/10/03)
- 1872 Seated Liberty dime with 175 degree rotation
- Distorted hub doubling (Class II)
- Design hub doubling (Class III)
- Offset hub doubling (Class IV)
- Pivoted hub doubling (Class V)
- Distended hub doubling (Class VI)
- Modified hub doubling (Class VII)
- Tilted hub doubling (Class VIII)
- Single-squeeze doubled dies (often attributed to Class VIII) (CW 2/14/05, 9/12/05)
- Centrally-located doubling (CW 3/21/22)
- Peripheral Doubling (CW 8/8/04)
- Weaker impression hubbed last (e.g., 1963-D cent) (CW 6/14/10)
- Centrally-located doubled dies (CW 4/15/19)
- Rotated
- Rotated hub doubling (Class I) (CW 8/8/16)
Weak or incomplete hubbing (always part of a doubled die)
Tilted hubbing (always part of a doubled die)
Misaligned hubbing (uncorrected) (CW 5/30/22)
Repunched dates (ES July/August 2012; CW 12/14/09)
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- 1956-D cent with repunched 5 (controversial) (CW 9/20/04, 7/16/12)
- 1957-D cent with repunched 7 (controversial)
Re-engraved dates (on master die or working die)
Blundered dates (on master die or working die)
Misplaced dates (e.g. digits in denticles) (CW 4/21/03)
Phantom mintmarks (working hub has mintmark incompletely removed)
-
- (e.g. faint D and S mintmarks in cents from the late 1990s)
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- 1980 D & S cent (recently delisted)
- 1956 D & S cent (controversial)
Horizontal mintmarks (inevitably repunched)
Tilted mintmarks (punched in at an angle) (CW 7/28/14)
Rotated mintmarks (CW 7/28/14)
Deeply-punched (high-standing) mintmarks (CW 9/29/14)
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- High-standing D mintmark (1987-D, 1988-D, and 1989-D cents)
Weakly-punched mintmarks
Repunched mintmarks (CW 1/20/20)
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- Overlapping mintmarks
- Totally separated mintmarks
- Two different fonts
- Large over small mintmarks
Repunched mintmarks on the Jefferson nickel; Book by James Wiles (downloadable version)
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- 1938-D/S Buffalo Nickel
- 1944-D/S cent
Other repunched or re-engraved design elements
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- 1982 “no-P” Roosevelt dime
- 1990 Lincoln proof cent without S-mintmark
COIN WORLD SPECIAL: article posted HERE on 1975-S Roosevelt dime without mintmark
Omitted dates (foreign only) (CW 4/28/14)
Different mintmark styles and sizes
Overdates (CW 1/23/17)
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- Caused by repunching or re-engraving
- 1892 over an 18(8)2 Peruvian 1/2 Dino
- 1958-D Lincoln cent with repunched 7 digit (debunked)
- Caused by second hubbing of different date (Class III doubled die)
- Caused by grinding off earlier design and rehubbing or repunching (CW 1/23/17)
- 1943 over 1942 Jefferson nickel
- Caused by repunching or re-engraving
Dual Dates (earlier date faint)
-
- Caused by erasing earlier date on working hub
- Caused by removing earlier date from working die and re-hubbing (e.g. 1975 Bahamas 5c with faint date “1973” on opposite face)
Wrong dates
-
- Date later than final date of issue (e.g., 1913 Liberty Head nickel)
- Date earlier than first date of issue (e.g., 1954 Mexico 5 centavos – small size)
- Wrong digits (e.g., 1393/1893 Peruvian peso)
- Transposed digits
Blundered dies (various types) (CW 8/18/08)
-
- Misspelling on working dies
- 1801 Large Cent: United misspelled IINITED
- 1863 Patriotic Token; SPOT misspelled (SPOOT)
Special Finish Errors (Proofs, Mint sets, Special Mint Sets, Satin Finish, etc.)
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- Frosting slop-over (proofs)
- Offset frosting (proofs) (CW 2/21/11)
- Design removed by proof polishing (CW 2/21/11)
- Field lowered by proof polishing (CW 2/14/11)
- Frosting applied in wrong place (CW 2/28/11)
- COIN WORLD SPECIAL: article posted HERE “Frosted Freedom” $50 and $100 platinum coins (CW 8/1/11)
- Frosting omitted
- Stencil outlines (CW 2/18/13)
- Incomplete Proof Laser Frosting (CW 9/12/16, 9/6/21)
Design Extension Dimples (CW 4/18/11)
-
- COIN WORLD SPECIAL: article posted HERE
Edge Lettering Font Variants
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- Presidential dollars (4-5 types) (CW 10/18/10)
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- Applied to working die or master die
- 1973 and 1974 Mexico Bronze 20 Centavos
- 1984 Mexico 1 Peso
- Applied to working hub
- 2023 “extra V” cent (CW 3/27/23)
- Applied to working die or master die
Part III. Die Installation Errors:
Mules (ES May/June 2010)
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- Wrong hammer die
- 2005 Malaysian 1 sen obverse die paired with 10 sen reverse die and struck on a copper-nickel 10 sen planchet in a 10 sen collar
- 1995 cent/dime mule
- Wrong anvil die
- Malaysian 1 sen reverse die paired with a 2005 10 sen obverse die and struck on a copper-nickel 10 sen planchet in a 10 sen collar
- 1993-D and 1999 cent/dime mules
- Wrong hammer and anvil die
- 2005 Malaysian 1 sen obverse and reverse dies used to strike a 10 sen planchet in a 10 sen collar
- Maryland quarter on Sac planchet in Sac collar (3 specimens)
- Two anvil dies
- Two hammer dies
- Two obverse or two reverse dies (die setup unclear)
- 2000-P nickel with two obverse dies (CW 6/26/17)
- Two different countries
- (1967) Bahamas 5c/New Zealand 2c mule
- Different denominations
- Washington 25c/Sacagawea $1 mules (16 specimens, 3 die pairs)
- COIN WORLD SPECIAL: article posted HERE
- Washington 25c/Sacagawea $1 mules (16 specimens, 3 die pairs)
- Mule die larger than normal die and collar
- 1995 cent/dime mule
- Mule die same size or smaller than normal dies and collar
- (All known U.S. mules employ dies of different sizes)
- Temporal mule (mule die representing same denomination but from an earlier or subsequent year) (CW 1/24/14)
- 1959-D wheat-back cent (unique)
- 2000 Macedonia 1 denar muled with obverse die used in prior and later years
- Temporal/transitional mule (dies from different years with change in planchet composition) (CW 5/9/16)
- 1942-S silver alloy five cent coin with small S-mintmark to right of Monticello (unique) (CW 5/9/16)
- 1993 bimetallic Russia 50 roubles (1992 St. Petersburg mint set only) (ES March/April 2010; CW 3/20/17)
- Regular-issue die muled with commemorative die
- Regular-issue die muled with government medal or token die
- Regular-issue die muled with private token, medal, or nonsense die (ES Jan/Feb 2008; CW 11/25/13)
- Mules involving pattern dies (various types)
- Normal die paired with pattern or prototype die (CW 2/2/04)
- Collar mules (collar from different denomination of same or similar size installed)
- Lettering die mule (mismatch between edge lettering applied before or after strike and the design shown on the obverse and reverse face)
- Presidential dollar with wrong date on edge.
- 2009 Zachary Taylor dollar with 2010-D edge inscription (rather than 2009-D inscription) (CW 2/22/10, 3/1/10)
- 2007-D Sacagawea dollar with Presidential dollar edge lettering (CW 7/9/12)
- Presidential dollar with wrong date on edge.
- Pseudo-mules (3 pathways)
(CW 4/25/11, 3/19/12, 4/23/12, 12/11/17, 12/17/18, 2/22/21, 12/12/22, 1/15/24)
COIN WORLD SPECIAL: article posted HERE
- Wrong hammer die
Mismatched business / proof dies
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- 1999 $5 and $10 gold eagles struck with unfinished proof dies (W-mintmark)
- 1998-2000 business strike cents with proof-style reverse (Wide AM)
- 1998-S and 1999-S proof cents with business-style reverse (Close AM)
- 1956 – 1964 quarters with “Type B” proof reverse
- 1956 – 1963 halves with “Type 2” proof reverse
- 1969-P, 1970-P and 1970-D Roosevelt dimes struck with 1968-S reverse proof dies
- 1939 proof Jefferson nickel obverse with 1938 reverse
- 1940 proof Jefferson nickel obverse with 1938 reverse
Finished proof die matched with business die
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- Early 19th century examples (CW 8/20/12)
Transitional Reverse (Minor temporal mismatches) e.g.:
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- 1939 nickel with reverse of 1938
- 1940 nickel with reverse of 1938 or 1939
- Proof 1940 nickel with reverse of 1938 (CW 4/19/08)
- 1964-D quarter with the “Type C” reverse of 1965
- 1988-D and P Lincoln cents with reverse of 1989
- 1992-D and P cent with “Close AM” reverse
- 2008-P Silver Eagle Bullion Coin with 2007-P Reverse
- COIN WORLD SPECIAL: article posted HERE
Inverted die installation (not an error) (CW 2/15/10, 7/22/19, 1/6/20)
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- Older issues struck with inverted dies (e.g. buffalo nickels and Mercury dimes)
- Re-introduction of inverted dies (beginning 1989) (CW 12/4/23, 12/11/23)
- Saddle strikes produced by inverted dies (CW 9/13/10, 9/19/16)
Late use of traditional die setup (CW 6/5/18)
Fixed rotated die errors (see Part VI)
Collar installation errors
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- Smooth edge instead of reeded edge (and vice versa)
- 1863 Indian cent with reeded edge (CW 6/3/02)
- Smooth edge instead of edge design (and vice versa)
- Reeded edge instead of edge design (and vice versa)
- Segmented proof collar with segments out-of-order (CW 4/7/08)
- 2007-S Proof Presidential dollar with segments arranged in wrong sequence (CW 4/7/08)
- Smooth edge instead of reeded edge (and vice versa)
Use of flat, featureless dies (CW 6/30/14)
Use of cancelled and defaced dies (CW 5/12/14)
Cancelation overstrikes (coins overstruck by canceled coin, pattern, or test dies) (CW 5/18/17, 5/24/21)
Design/composition mismatches (CW 2/10/20)
Part IV. Die Errors:
Reeding vs. no reeding varieties (foreign only)
Concentric lathe lines (ES Nov/Dec 2003)
-
- Various years and denominations
- Common on the 1996-D Lincoln cent
- Various years and denominations
Rusted dies (CW 12/1/08)
Excessively deep rim gutter
-
- 1991 cents
Rockwell test mark left in die (hemispherical bump seen on coin) (ES July/Aug 2006)
Vickers test mark left in die (pyramidal bump) (CW 5/15/17)
Collar manufacturing errors
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- Wide collar (ES Nov/Dec 2002; CW 5/17/10)
- Created by improper machining or improperly machined broach
- Created by use of wrong broach
- Improper use of correct broach
- Widening due to wear
- Widening due to 3 or more vertical collar cracks and associated expansion (CW 5/17/10)
- Abnormal reeding
- 1921 Morgan dollar with infrequent reeding
- 1924-D Mercury dime with infrequent reeding
- 2015 American Eagle 1/10 oz. gold bullion coin with narrow reeds (CW 7/13/15)
- Low, narrow reeds caused by truncation of ridges on collar face (ES March/April 2010; CW 1/25/10, 4/16/12)
- 1964-D 25c
- 2008-P New Mexico 25c
- COIN WORLD SPECIAL: article posted HERE
- Wide collar (ES Nov/Dec 2002; CW 5/17/10)
Hub retouching
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- Channeling (hub retouching affecting working and master hubs from the 1920s to 1940s) (CW 7/23/12)
- Re-engraved master hub (CW 1/1/24)
- Channeling (hub retouching affecting working and master hubs from the 1920s to 1940s) (CW 7/23/12)
Die retouching (CW 5/30/16, 9/30/19)
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- Re-engraved designer’s initials “AW” on 1944-D half dollar (CW 2/2/04, 2/16/04, 3/1/04)
- Re-engraved tail feathers on business-strike 1957-D quarter
- Re-engraved front of Lincoln’s coat (1953 proof cent)
- Re-engraved working dies and hubs on Lincoln cents (CW 9/30/19)
- Re-engraved queue on 1952 – 1954 proof nickels
- 1938 proof nickels with re-engraved letters and design details (ES Jan/Feb 2009)
- Retouching of the 1944 date on the Lincoln cent master die
- Retouching of the date on 1946-S Lincoln cent working dies
- Re-engraved designer’s initials “AW” on 1944-D half dollar (CW 2/2/04, 2/16/04, 3/1/04)
Die damage (ES Jan/Feb 2003, Nov/Dec 2004; CW 5/21/12)
-
- Die dents
(ES Nov/Dec 2004, July/August 2005, Nov/Dec 2005; CW 9/15/03, 12/22/14, 3/28/22, 7/31/23) - Die scrapes (CW 4/23/07)
- Accidental die scratches
- Die gouges
- Impact scars
- Accidental die abrasion (CW 9/8/14, 12/16/19)
- Intentional die abrasion (“die polishing”) (CW 3/29/10, 5/31/10, 9/8/14, 3/20/23)
- Heavy die scratches
- Thinning and loss of design elements
- Two Feather Indian Head Nickel (various dates)
- 3-legged Indian Head Nickel (1937-D)
- 3 ½ legged Indian Nickel (1936-D)
- Abrasion affecting entire die face
- Localized abrasion
- Defects related to die polishing
- Over-polished proof and Special Mint Set dies (CW 2/21/11)
- Trails and Wavy Steps (ES July/Aug 2006, Sept/Oct 2006, Nov/Dec 2006, Jan/Feb 2011; CW 3/8/10)
- Localized removal of field from proof polishing (CW 2/14/11)
- COIN WORLD SPECIAL: article posted HERE
- Die attrition errors (ES May/June 2003, March/April 2005, March/April 2009; CW 1/4/10, 12/24/12, 4/14/14, 11/4/19, 7/3/23, 10/16/23)
- Other forms of peripheral die damage (ES March/April 2005; CW 8/9/21, 3/14/22)
- Catastrophic die damage (ES March/April 2002; CW 9/15/03, 9/12/11, 9/19/11, 5/20/13, 10/27/14, 6/19/17)
- Cancelled or defaced dies (foreign only) (CW 5/8/17, 12/31/18)
- 1994 Hong Kong bimetallic 10 dollars
- Egypt 25 piastres struck by defaced 50 piastres dies (CW 5/12/14)
- 1966 Bolivia 10 centavos struck by pair of canceled dies (CW 5/8/17)
- Chilean test dies with concentric cancellation pattern struck over struck foreign core (CW 5/8/17)
- Rockwell test mark in die (CW 5/15/17)
- Vickers test mark in die (CW 5/15/17)
- Die rings (tiny rings, semicircles, crescents, and spirals) (CW 2/20/17, 1/18/21, 6/13/22)
-
- Centrally-located
- Offset
-
- Collar damage (ES March/April 2010; CW 1/25/10, 4/16/12, 6/17/19)
- Horizontal abrasion (CW 1/25/10, 4/16/12)
- Vertical abrasion (CW 6/17/19)
- Die dents
Hubbed-In debris (CW 5/27/13)
Deformed collar (CW 12/18/20)
Clashed dies (ES March/April 2002; CW 3/22/10, 4/30/12)
-
- Clash marks
- Multiple clash marks (CW 6/25/12, 11/11/19)
- Raised clash marks (CW 8/11/14)
- Double clash with reciprocal counterclash (Type I) (ES Nov/Dec 2004; CW 12/13/10, 7/29/19)
- Misaligned die clashes (ES May/June 2004, July/August 2004; CW 6/25/12)
- Horizontally misaligned die clash
- Vertically misaligned (tilted) die clash (CW 1/3/11, 5/9/11)
- COIN WORLD SPECIAL: article posted HERE
- Pivoted die clash
- Radically misaligned, rotated, pivoted clashes – produced at installation? (CW 7/12/10, 12/31/12, 5/27/19)
- Co-occurrence with conventional clash (CW 8/17/15)
- Rotated die clash (CW 1/22/18, 6/26/23)
- Combination clashes
- Mule clash errors, e.g. (ES July/August 2002; CW 11/17/08, 8/13/18, 8/20/18, 4/8/19)
- 1864 2c reverse die clashed with Indian cent obverse die
- 1857 1c obverse die clashed with Seated Liberty 50c obverse die
- 1857 1c reverse die clashed with Seated Liberty 25c reverse die
- 1857 1c obverse die clashed with Liberty $20 obverse die
- (For detailed information concerning the 1857 die clashes CLICK HERE)
- 1857 Seated Liberty 25c reverse die clashed with 1857 1c reverse die
- 1870 Shield nickel obverse clashed with Indian Head cent obverse
- 1999 cent reverse die clashed with another cent reverse die
- Floating die clash (collision with die fragments) (ES May/June 2002, May/June 2005; CW 7/19/10)
- Superclash (full reciprocal design transfer) (CW 3/22/10, 10/22/18)
- Circumferential clash marks (CW 12/10/18)
- Grease-enhanced clash marks (CW 10/16/17)
- Associated with weak strikes (CW 12/2/19)
- Clashed die progressions (CW 5/15/23)
- Clash marks
Collar clash (CW 6/11/07, 2/24/22)
-
- Hammer die
- Anvil die
- Inverted die setup (uncommon)
- Traditional die setup (extremely rare) (CW 10/30/23, 12/18/23)
- Floating collar clash (CW 4/17/17)
- Misaligned collar clash (CW 2/13/23)
Die damage with design transfer
-
- Floating die clash (ES May/June 2002, May/June 2005; CW 7/19/10)
- Exogenous floating die clash (CW 6/20/22)
- Floating (Type 2) counterclash (ES May/June 2002, July/August 2002, Sept/Oct 2002, Jan/Feb 2009, Sept/Oct 2011; CW 9/29/08, 12/13/10, 4/9/12, 4/21/14, 6/8/15, 4/23/18, 2/21/22, 12/19/22, 2/20/23)
- COIN WORLD SPECIAL: article posted HERE
- Miscellaneous and unexplained forms of design transfer/duplication
- Some presumed Canadian counterclashes may prove to be something else
- Floating die clash (ES May/June 2002, May/June 2005; CW 7/19/10)
Die deterioration/deformation errors
-
- Exaggerated conventional die wear (CW 12/27/21)
- Radial flow lines
- Concentric flow lines (uncommon)
- Parallel flow lines (promoted by pre-existing trails)
- Orange peel texture
- Design-devouring die wear (thinned letters and numbers)
(CW 10/28/13, 2/22/16, 8/23/21)
- Discrete lumps (CW 4/27/20)
- Die deterioration doubling
- Raised doubling
- Incuse (CW 2/4/08)
- “Blebs” or “patches” (die erosion pits) (ES July/Aug 1998; CW 7/21/03)
- Progressive, indirect design transfer (“internal metal displacement phenomenon”, “ghosting”) (CW 6/7/10, 8/17/20)
- Common in 1946-S and 1948-S cents
- Surface-level die deformation errors (ES July/Aug 2001, Nov/Dec 2001; CW 9/17/12) (premature, localized, exaggerated, and peculiar patterns of deformation)
- 1943-S “goiter neck” quarter
- Detail-erasing die wear (2016-P Harper’s Ferry quarter) (CW 2/27/17)
- “Ridge rings”
- On copper-plated zinc cents (CW 2/14/05, 2/28/05)
- On other U.S. denominations (CW 2/15/21)
- On world coins (ES Sept/Oct 2006; CW 2/17/14, 11/10/14)
- Design berms (raised outlines) (CW 5/14/18, 11/6/23)
- Die subsidence (sunken die) error (ES July/August 2004, Nov/Dec 2004; CW 6/2/03, 11/29/04, 3/12/12, 2/12/18, 8/14/23)
- e.g., 1924-S – “goiter” cent
- Co-occurring with split dies
- Co-occurring with radial, antipodal die cracks (CW 6/20/11)
- 1988-P nickels with lump on head
- COIN WORLD SPECIAL: article posted HERE
- Massive die collapse in 2003-D dime (ES, Nov/Dec 2011; CW 8/29/11)
- Paralleling and flanking die cracks (CW 8/12/13)
- Recurring die subsidence error (CW 4/4/11, 3/31/14)
- Linear die subsidence errors (CW 8/12/13)
- Thermal warping (CW 5/29/23)
- Design creep
- Reverse (hammer) 2014-P nickel die (CW 4/20/15)
- In fractional Euro coins
- Peripheral die expansion and erosion (CW 8/13/12, 4/13/15)
- “Starburst” pattern of radial streaks (cause uncertain) (CW 8/15/05, 11/7/05)
- Reciprocally deformed, convex-concave dies
- Centrally-located deformation; 2001-P 50c) (ES Sept/Oct 2008; CW 1/19/15)
- Peripherally-located deformation; India 2 rupees (CW 1/19/15)
- Exaggerated conventional die wear (CW 12/27/21)
-
- Cuds (corner die breaks) (CW 10/17/11, 10/4/21)
- Irregular cuds
- Ovoid cuds
- Crescentic cuds (ES March/April 2005; CW 2/15/16)
- Circumferential cuds (ES March/April 2005; CW 2/15/16)
- Rim-to-rim cuds (ES May/June 2003, CW 12/24/18)
- Elongate cuds (CW 12/8/14, 12/21/20, 7/31/23)
- On off-center or broadstruck coins (CW 9/12/11)
- Deep vs. shallow die breaks (CW 6/2/20)
- Retained Cuds (ES Jan/Feb 2006; CW 4/17/06, 7/24/06, 1/24/11)
- COIN WORLD SPECIAL: article posted HERE
- Anvil die (diagnosis often in doubt)
- Hammer die (doubtful) (CW 8/8/13)
- With vertical displacement
- With horizontal offset
- With lateral spread
- Outthrust Die Fragment (protrudes beyond die face) (CW 3/11/19)
- Hammer die
- Anvil die
- Interior (internal) die breaks (ES May/June 2003; CW 10/25/10, 11/5/18, 8/14/23)
- Connected to die cracks or splits
- Freestanding (ES May/June 2005)
- Retained interior die breaks (ES July/August 2004)
- Rim cuds (CW 5/3/21)
- Die chips (CW 6/14/19, 7/8/19)
- On raised die features (CW 2/28/22)
- Catastrophic die failure (ES May/June 2007; CW 5/20/13, 2/27/23, 6/19/23)
- Spontaneous breaks
- Breaks produced by impacts
- Textured and dimpled cuds (CW 10/17/11, 10/12/20)
- Cryptic cuds (CW 4/17/23)
- Cuds (corner die breaks) (CW 10/17/11, 10/4/21)
Die exfoliation errors (CW 10/19/20)
Collar breaks (collar cuds) (ES May/June 2008; CW 11/22/10, 5/17/10, 11/22/10, 12/19/16)
-
- Complete collar break (abrupt loss of entire arc segment)
- Irregular collar break
- Chipped collar
- Vertical collar crack
- Retained collar break
- Rotating collar break (ES July/August 2003; CW 1/6/03, 12/12/16, 4/20/20, 12/28/20)
- Bilateral split collar
- On off-center strikes (CW 9/9/19)
- Catastrophic collar failure (CW 7/17/23)
Die cracks (CW 4/25/16)
-
- Rim-to-rim
- Arcing rim-to-rim (“pre-cud”) die crack (ES Jan/Feb 2006; CW 2/8/21)
- With lateral spread
- Blind-ended
- Bi-level die cracks (ES July/August 2004)
- Protruding marginal die segments (CW 5/19/14)
- Radial, antipodal die cracks (with centralized subsidence) (ES Sept/Oct 2011; CW 6/20/11)
- Die Crazing (Crazed Die)
- Shattered dies (ES Jan/Feb 2006, May/June 2007; CW 4/7/08, 9/17/18, 4/6/20)
- Broas Pie Baker Store Card Token of 1863
- Two or more splits in die
- Numerous wide, intersecting, raised die cracks
- Numerous intersecting bi-level die cracks
- Various combinations of brittle fracture
- In response to impacts (CW 6/19/17)
- Impact-Induced Die Cracks (CW 6/19/17)
Split dies (ES Jan/Feb 2006; CW 6/2/03, 4/10/06, 4/17/06, 6/20/11, 5/11/15, 9/17/18, 4/26/21, 4/18/22, 7/18/22)
-
- Median (bisecting) split die
- Asymmetrical split die (CW 7/31/23)
- False split (radial, antipodal die cracks) (ES Sept/Oct 2011; CW 6/20/11)
Part V. Planchet Errors:
Alloy errors
-
- Improper alloy mix (CW 12/27/11, 1/30/23, 4/3/23)
- Poorly mixed alloy
- Incorrect proportions of metals
- In conjunction with rolled-thick errors (1941 cents, mainly) (CW 10/15/12)
- Gas Bubbles (CW 11/19/12)
- Intact (“occluded”)
- Ruptured
- Slag inclusions (ES May/June 2006)
- Intrinsic metallic inclusions (ES Sept/Oct 2006; CW 12/27/10, 12/27/11, 7/21/14)
- Lamination errors
- Loss before strike
- Loss after strike
- Lamination cracks
- Retained laminations
- Folded-over before strike (CW 10/22/12)
- Internally split clad layer (CW 10/22/12, 6/26/17)
- Split planchets
- Before strike (CW 8/2/10)
- After strike
- Wrong Denomination / Off-metal
- Struck with another planchet on top or beneath
- Split core (clad coins)
- Clamshell split (CW 1/28/13)
- Clamshell folded over before strike (CW 10/22/12, 1/28/13)
- Hemi-split planchets (CW 10/9/23)
- Copper-and-zinc composite “shells” (ES May/June 2001)
- Split-after-strike (N.B. these are probably all detached cap bottoms)
- Cracked planchets
- Broken planchets / coins (CW 3/14/11, 9/18/23)
- Before strike
- After strike
- Brittle coins (cross-classified with annealing errors)
- Radial planchet splits (when struck out-of-collar)
- Delayed radial stress splits (CW 5/2/22)
- Planchet cohesion errors (crumbling planchets) (CW 11/22/21)
- Ragged clips CW 2/29/16)
- Ragged notch
- Ragged perforations (“blowholes”)
- Fissures — ragged and smooth
- Stress-induced surface irregularities (CW 4/24/17)
- Rolling-Induced Fissures
- Improper alloy mix (CW 12/27/11, 1/30/23, 4/3/23)
Subsurface Corrosion (CW 12/21/15)
-
- Plated coins
- Copper-plated zinc cents
- Solid coins
- Plated coins
Rolling Mill Errors
-
- Rolled-thick planchets
- Rolled-thin planchets (CW 8/2/10, 7/16/18)
- Tapered planchets (CW 12/20/10, 12/28/15)
- On clad coins (clad layer absent) (CW 4/27/15)
- Rolling indentations (ES Jan/Feb 2000; CW 2/7/11)
- Rolled-in scrap (ES May/June 2006; CW 2/7/11)
- Bristles from descaling brush (CW 3/10/03)
- Roller marks (CW 10/13/14)
- Rolled-in patterns and textures
- Rolled-in cloth pattern (CW 3/21/16)
Blanking and Cutting Errors
-
- Definition
- Curved (concave) clips (CW 6/29/15)
- Crescent curved clips
- Bowtie clips (ES Nov/Dec 2005; CW 6/16/14)
- Two large clips at opposite poles – ends rounded
- Four clips — punch slices through strip with normal hole spacing
- Struck chopped webbing
- Straight clips (CW 1/14/13)
- Smooth straight clips
- Irregular straight clips
- Sawtooth clips
- Incomplete straight clips (actually struck-in cutting burrs)
- Straight cutting burrs (CW 1/14/13, 5/16/16)
- Corner clips (“outside corner clip”) (CW 1/14/13)
- Assay clips (“inside corner clip”) (cross-classified with pre-strike damage) (CW 1/21/13, 6/12/17)
- Ragged clips (also listed under alloy errors)
- Incomplete punch (incomplete clip) (ES May/June 2005; CW 3/24/14)
- Elliptical (convex) clips (ES May/June 2005; CW 4/5/10, 7/11/11)
- Multiple clips and combination clips (CW 1/27/14)
- Blanking burrs (“rolling fold”) (ES Jan/Feb 2007; CW 1/31/11, 5/29/17, 9/4/23)
- COIN WORLD SPECIAL: article posted HERE
- Concave blanking burrs (CW 5/16/16)
- Punched-in scrap (ES May/June 2006)
Upset Mill Errors
-
- Coins struck on blank (“Type I planchet”)
- Abnormally weak upset (ES July/August 2005)
- Abnormally strong upset (best seen on off-center strikes)
- “Groovy edge” (possibly from worn groove in upset mill)
- Variation in cross-sectional shape of rim/edge junction of planchet
- Struck coin sent back through upset mill
- Abnormal upset (ES Sept/Oct 2005; CW 2/27/12, 11/21/16)
- Wide, flat edge
- Smoothly convex edge
- Abnormally wide proto-rim
- Squeezed-in debris (upset mill inclusion) (ES May/June 2006; CW 9/6/10)
- Foil-like metal wraps around edge onto one or both faces
- e.g. Copper foil on nickels (not from improper annealing)
- Metal wire wraps around edge onto one or both faces
- Pellet embedded in edge (CW 9/6/10, 9/22/14)
- Foil-like metal wraps around edge onto one or both faces
Edge design errors (impressed into planchet before strike) (includes security edge errors) (CW 6/27/16)
-
- Edge design missing
- Edge design present on normally plain edge (CW 6/27/16)
- Wrong edge design
- Edge design too high or too low
- Interrupted edge design
- Tilted edge design
- Broken edging die (CW 6/27/16)
Mispunched center holes (foreign only) (CW 1/7/19)
-
- Misaligned holes
- Double punched center holes
- One hole centered
- Both holes misaligned
- Overlapping holes
- Totally separate holes
- Irregular center holes
- Abnormally small hole
- Partial hole (from broken hole punch)
- Circular Indentation (partial penetration)
- Due to broken-off punch tip
- Unpunched center hole
- Hole punched in planchet meant for a solid coin
Annealing Errors
-
- Improper annealing (due to excessive heat, prolonged exposure to intense heat, or excessive oxygen in annealing oven) (replaces “sintered plating” and “copper wash”) (ES July/Aug 2010; CW 11/30/09, 2/8/10)
- Black, brown, red, coppery discoloration (includes “black beauty” nickels)
- Layer of copper, often peeling
- Improper annealing (due to excessive heat, prolonged exposure to intense heat, or excessive oxygen in annealing oven) (replaces “sintered plating” and “copper wash”) (ES July/Aug 2010; CW 11/30/09, 2/8/10)
Poorly annealed or unannealed planchets (hard, brittle planchets) (CW 3/14/11)
-
- Broken planchets and coins (CW 3/14/11, 9/18/23)
- Radial cracks in coin (usually struck out-of-collar)
Brittle coins (cross-classified with alloy errors) (CW 3/14/11)
Abnormally hard planchets (CW 12/17/12, 8/15/22)
-
- 1954-S nickels
- 1983-P nickels
- COIN WORLD SPECIAL: article posted HERE
- “Superclash” 2000-P nickel (CW 3/22/10)
On undersized or underweight planchets (CW 2/13/12)
Miscellaneous forms of mint discoloration
Plating Errors
-
-
- Incomplete plating
- Unplated cents (CW 10/26/15, 7/24/23)
- Cents struck on unplated or partly-plated foreign planchets (CW 3/10/14)
- Thin plating
- Thick plating (ES March/April 2009)
- Blistered plating
- Circular blisters
- Linear blisters
- Intact blisters
- Ruptured blisters
- Brassy plating
- Split Plating (CW 12/18/17)
- Cracked and Peeling Plating (CW 12/18/17)
-
Bonding/Bonding Mill Errors (ES Sept/Oct 2002)
-
- Missing clad layer
- Full
- Before strike (CW 5/23/22)
- After strike
- Before rolling is completed (weight may be close to normal) (ES Sept/Oct 2002, Nov/Dec 2006; CW 5/28/12)
- Partial
- Before strike
- After strike
- Before rolling is completed
- Thin cladding
- With gaps
- Missing both clad layers (struck core)
- Core thickness (ES Sept/Oct 2003; CW 3/18/13, 2/3/20)
- Full thickness
- Full
- Struck Clad layer
- Separated after strike
- COIN WORLD SPECIAL: article posted HERE
- Separated before strike
- Struck by itself
- Struck on top of or beneath a normal planchet
- Separated after strike
- Clamshell separation (CW 1/28/13)
- Clad layer folded over before strike
- Missing core
- Partial
- Full (Coreless or all-clad coins) (CW 12/19/11)
- Missing clad layer
Irregular planchets
-
- Scraps/fragments (CW 12/21/09, 1/27/20)
- Normal alloy/composition
- Off-metal
- Feeder finger material
- Foil
- Heavier than normal coin of same denomination
- Wider than normal coin of same denomination (along at least one axis)
- Ragged clip (cross-classified with alloy errors)
- Ragged notch (cross-classified with alloy errors)
- “Blowholes” (cross-classified with alloy errors)
- Fissures (cross-classified with alloy errors)
- Cracked planchets (cross-classified with alloy errors)
- Scraps/fragments (CW 12/21/09, 1/27/20)
Pristine Planchets (i.e. lacking tumbling marks) (CW 1/11/16)
Pre-Strike Damage (CW 11/15/10, 11/15/10, 1/23/12, 1/30/12, 12/15/14, 4/13/15, 6/8/20)
-
- COIN WORLD SPECIALS: articles posted HERE and HERE
- Assay clips (cross-classified with blanking errors)
- Rim burrs (CW 1/31/11)
- Accidentally and intentionally “re-sized” planchets (CW 9/15/10)
- “Crimp marks” (mostly found on off-metal errors, e.g., 5c/1c, 5c/10c)
- Rockwell test mark in planchet (circular or oval dimple) (ES July/Aug 2006; CW 10/15/18)
- Planchet with adjustment marks (gold and silver planchets filed to return heavy planchets to normal weight)
- Edge rolled, squeezed, and folded-over (or with thin apron produced) (CW 11/15/10, 1/23/12, 6/15/20)
- Pre-plating damage (zinc cents) (CW 1/23/12)
- Post-plating damage (zinc cents) (CW 11/15/10)
- Scraped-in debris (CW 2/23/15)
- Repetitive pre-strike damage (CW 12/15/14)
- Other forms of pre-strike damage
- Gouged (CW 1/14/19)
- Crushed (CW 4/13/15)
- Scraped (CW 2/23/15)
- Torn
- Crumpled (CW 8/15/11)
- Gouged (CW 1/14/19)
Inter-strike Damage (CW 1/9/12, 8/20/12)
-
- Cancelled or defaced between strikes (CW 3/25/13)
Trans-strike damage (CW 7/12/21)
Wrong planchet and off-metal errors
-
- Wrong planchet, correct composition
- Off-metal
- Domestic planchet (CW 6/22/20)
- Monroe dollar coin struck on a clad dime planchet
- 1987-P Jefferson nickel struck on clad stock
- Domestic struck on foreign planchet
- 1941-P Lincoln cent struck on a Panama 1¼ bronze centesimos
- 1920-P Lincoln cent struck on a Argentina 10 centavos planchet
- 1905-P Barber dime struck on a Panama or Philippines five centavos planchet
- 2000-P Sacagawea struck on a Ghana 100 Cedis ring
- Foreign planchet
- Unidentified origin and purpose (orphan) (ES Sept/Oct 2006, Nov/Dec 2006, March/April 2011, May/June 2011; CW 5/10/10, 12/19/11, 1/30/17, 11/30/20, 4/4/22)
- Defective and damaged off-metal planchets (CW 3/21/16)
- Foreign denomination struck on U.S. planchet
- 1970 Philippines 25 Sentimos on a U. S. cent planchet (3.1 g)
- 1972 Philippines 1 Peso on a U.S. clad 50 cent planchet
- 2000 Canadian Pride 25 cent coin struck on a United States nickel planchet
- Pure copper quarters and dimes (covered under bonding mill errors)
- Pure clad dime (covered under bonding mill errors)
- Domestic planchet (CW 6/22/20)
- Wrong stock errors
- Correct composition
- Off-metal (e.g, 1987-P nickel struck on clad quarter stock) (CW 4/22/13, 9/23/13, 9/10/18)
- Transitional stock planchets (CW 9/23/13)
- Business strike on off-metal special planchet (CW 2/10/20)
- (e.g., 40% silver-clad 1974-D and 1977-D Eisenhower dollars)
- Special strike on off-metal business planchet (CW 2/10/20)
- (e.g., 1973-S Eisenhower dollar on Cu-Ni clad planchet)
- Business strikes on proof planchets (CW 11/14/11)
- Proof strike on business planchet
- COIN WORLD SPECIAL: article posted HERE
- Wrong date error (covered under mules and die manufacturing errors)
- Double denomination errors (CW 10/3/22)
- Same year
- Different year
- Over pre-existing wrong planchet/off-metal error (ES Sept/Oct 2017; CW 2/10/14)
- Dual country (CW 3/21/11)
- Same year
- Different year
- Intentional overstrikes (not an error)
- Transitional planchet errors (“wrong series”) (ES Sept/Oct 2001; CW 3/28/16, 8/22/16)
- Composition/year mismatch with non-overlapping production schedule
- 1943 bronze cents (CW 4/11/16)
- Composition/year mismatach with overlapping production schedule
- 1965 silver dimes and quarters
- 1964 clad dimes and quarters
- Intra-year design/composition mismatch
- 1991 Russia 10 kopek (ES Sept/Oct 2001)
- Forward-jumping transitional planchet errors (CW 3/20/17)
- “Long pause” transitional planchet errors (CW 4/5/21)
- Transitional/wrong denomination error
- (e.g. 1965 quarter struck on silver dime planchet)
- Composition/year mismatch with non-overlapping production schedule
- Struck on smaller planchet or coin
- Struck on same size planchet or coin
- Struck on re-sized planchet (dime design struck on cut-down cent planchet)
- Struck on larger planchet or coin (CW 8/22/22)
- 1981 cent on nickel planchet, uniface reverse
- 1981 dime on cent cap
- 1981 cent design struck on Susan B. Anthony dollar (several known)
- 2006 Chilean 10 pesos struck on a 100 pesos bi-metallic planchet
- Canadian “assisted errors” 1977 – 1981
- Malaysian “assisted errors” 2005 – 2007
- Struck on loose clad layer (covered under bonding mill errors)
- Weld seam planchets (controversial) (CW 9/24/12)
- Coins struck on washers, gears, and other hardware
- Coins struck on “aluminum” feeder fingers
- Experimental issues (CW 11/23/15, 5/23/16)
- Experimental wartime planchets (CW 12/7/09, 12/21/09)
- 1999 and 2000 state quarters on experimental planchets – tests for Sacagawea dollar (CW 11/26/01)
- 1999 Susan B. Anthony dollars struck on experimental planchets (CW 8/5/02)
- 1974 aluminum and bronze-clad steel cents (CW 1/13/03)
Bi-metallic errors (foreign only) (ES Nov/Dec 2005)
-
- Misaligned core (ES May/June 2007; CW 3/6/23)
- Misaligned center hole (ES Sept/Oct 2007)
- Well-seated core (CW 3/6/23)
- With misaligned core (CW 3/6/23)
- Double-punched center hole
- Unpunched center hole
- Solid disc of ring metal (CW 3/26/18)
- Solid disc of ring metal with embedded core
- Solid disc of ring metal with core indent
- Ring with incomplete punch (ES Sep/Oct 2007)
- Core with incomplete punch
- Struck outer ring (ES Jan/Feb 2007)
- Struck core (ES Nov/Dec 2006)
- From another denomination
- From another country (ES Sep/Oct 2009, Nov/Dec 2011)
- Struck by solid-denomination dies
- Wrong core inserted (ES Sep/Oct 2013; CW 10/17/22)
- Core-sized scrap disc of ring material inserted into disc
- Wrong ring (ES March/April 2007; CW 10/10/22)
- Ring accidentally punched from solid planchet
- Ring accidentally punched from solid coin (ES Nov/Dec 2008)
- Struck ring from another country (restruck)
- Struck core from another country (restruck)
- Unstruck core inserted into struck ring and then restruck
- Abnormally small core (controversial)
- Abnormally wide center hole (controversial)
- Abnormally thin core
- Abnormally thick core
- Abnormally thin ring
- Abnormally thick ring
- Incomplete trilaminar core
- Missing one layer (ES Mar/Apr 2010)
- Missing two layers
- Core punched out of ring strip
- Ring punched out of core strip
- Bi-metallic planchet struck by solid-denomination dies
- Solid-denomination planchet struck by bi-metallic dies (ES Mar/Apr 2014)
- Bi-metallic planchet struck by wrong bi-metallic design
Part VI. Striking Errors
Unstruck blank (“Type I”)
Unstruck planchet (“Type II”)
Die alignment errors
-
- Rotated die errors (CW 6/21/10, 7/9/12)
- Rotated die due to improper installation (fixed rotation)
- Rotated die due to improper die preparation (fixed rotation)
- (e.g., grinding flats in wrong spot)
- Rotated die due to movement after installation (dynamic rotation)
- Semi-stable rotated die errors (various causes)
- Characterized by a limited range of motion, a limited number of positions, or the presence of a single dominant position (CW 7/9/12, 8/7/23)
- Pivoted die errors (probably involves entire die assembly) (CW 6/22/15, 10/21/19)
- Alignment with off-center strikes (CW 8/19/19, 8/26/19)
- Horizontal misalignment (CW 10/27/03, 7/25/16)
- Hammer die (CW 2/1/10, 6/25/12)
- Anvil die (ES Sept/Oct 2004, March/April 2005; CW 9/27/10, 1/19/15, 1/4/21, 7/19/21)
- With misaligned collar
- With broken collar
- Dynamic misalignment (CW 6/25/12, 11/23/20)
- Multiple misaligned strikes (CW 10/11/21, 11/29/21)
- Stable misalignment
- On double-struck coins
- On first strike only (CW 8/31/20)
- On second strike only (CW 5/19/08, 5/23/11, 9/19/13)
- On both strikes
- Alignment with off-center strikes (CW 8/19/19, 8/26/19)
- Rotated die errors (CW 6/21/10, 7/9/12)
- Vertical misalignment (tilted die error) (ES Jan/Feb 2003, Sept/Oct 2003; CW 12/8/03, 12/20/10, 8/24/15, 10/24/16, 1/8/24)
- Hammer die (CW 2/1/10, 6/17/13)
- Anvil die
- Dynamic misalignment (CW 10/24/16)
- Stable misalignment (CW 1/29/14)
- Associated with weak strike (? 2/1/10, 10/8/12, 8/16/21)
- Associated with off-center strike (? 8/13/18)
- Dual misalignments (dies often misaligned in different directions) (CW 11/28/11, 5/18/15, 1/9/17, 7/9/18, 8/26/19)
- Compound misalignments (CW 8/24/15)
- Horizontal and vertical
- Horizontal and rotated
- Rotated and vertical
- Horizontal, rotated, and vertical (CW 8/26/19)
- Forced misalignments (CW 8/28/17)
Collar alignment errors
- Misaligned collar
- Associated with misaligned anvil die
- Associated with stiff collar error
- Associated with elliptical strike clip
- Rotating collar (detectable only when there’s a collar break and a multi-coin progression)
Collar deployment errors
-
- Partial collar (CW 2/24/20)
- Flange with bevel
- Flange without bevel
- Tilted partial collar
- Undulating partial collar (CW 2/24/20, 7/25/22)
- Re-entry partial collar
- Incomplete ejection partial collar (CW 12/26/22)
- Reversed partial collar (not an error)
- Multiple steps (CW 3/15/21)
- High deployment of collar with coin metal extruded beneath (doubtful)
- Broadstrikes
- Centered
- Uncentered (CW 7/20/15)
- Cupped broadstrike
- Forced broadstrike (CW 1/10/11, 11/30/15)
- Partial collar broadstrike (shows incomplete, tilted partial collar)
- Stiff collar errors (ES Nov/Dec 2000; CW 8/25/08)
- Normal die installation
- Inverted die installation
- Association with misaligned dies
- Association with misaligned collar
- Strong collar scar
- Strong collar scar with cupping
- Planchet forced completely into fully deployed collar (“ram strike”) (ES Nov/Dec 2000, March/April 2001)
- Elliptical strike clip (ES March/Apr 2000; CW 4/5/10)
- Associated with weak strike (CW 2/11/13)
- Collar shimmy (CW 8/21/17, 9/11/17)
- Partial collar (CW 2/24/20)
Weak Strikes (ES Sept/Oct 2000; CW 5/3/04, 9/11/06, 6/18/07, 3/1/10, 5/23/11, 6/23/14, 8/27/18, 3/2/20, 10/26/20, 11/27/23)
-
- Caused by insufficient die approximation
- Caused by abnormally low ram pressure
- Invisible strikes (ES March/April 2003, Nov/Dec 2003, March/April 2004, Nov/Dec 2006, May/June 2010; CW 5/3/10, 9/20/10)
- With indent
- With partial brockage
- With struck-through error
- Followed/preceded by strong strike (CW 7/13/20)
- Stable series of weak strikes (CW 8/27/18)
- Weak saddle strike
- One strike weak, one strong (CW 4/8/13)
- Both strikes weak (CW 12/12/11)
- In combination with other striking errors
- Rim-restricted first strike (CW 3/1/10, 10/10/11, 1/11/16, 2/19/18, 9/23/19)
- Rim-restricted second strike (CW 9/21/15, 2/13/17)
Skidding Coin Errors (CW 1/29/18)
Abnormally Strong Strikes
-
- Due to elevated ram pressure
- Finning (CW 8/23/04, 7/6/20)
- Encircling pressure bumps (CW 12/2/23)
- Due to elevated ram pressure or reduced minimum die clearance
- Due to stacked coins or planchets (CW 12/7/20)
- Localized, due to die tilt
- Due to elevated ram pressure
Stutter Strikes (ES Nov/Dec 2001, Sept/Oct 2007; CW 12/28/09, 7/25/11, 8/10/20)
-
- Due to spasmodically collapsing or stiff collar (Type I)
- Due to planchet flexion (associated with indents and brockages) (Type II)
- Due to contact with bent planchet or coin (Type III)
- On face struck by anvil die (CW 8/26/13)
Concentric strike lines generated by a single strike (ES Jan/Feb 2012; CW 12/26/11)
Machine doubling (a.k.a. machine doubling, machine doubling damage, machine damage doubling, mechanical doubling, strike doubling, shift doubling, ejection doubling) (ES July/Aug 2006; CW 3/15/10, 7/24/17, 12/23/19, 3/30/20)
-
- “Push doubling” (marginal shelving and sharp interior duplication) (CW 1/9/23)
- “Slide doubling” (smeared design) (CW 8/14/17)
- Rotational machine doubling (CW 8/10/15)
- Intermediate forms
- Multiple machine doubling in one direction (two, three, and four offset ranks)
- Machine doubling in more than one direction (up to three directions)
- Machine doubling on both faces of same coin (CW 3/15/10, 12/23/19)
- Rim-restricted design duplication (see separate category)
- Affecting incuse design elements (CW 2/6/06, 1/16/12)
- Located on top of die break
- Located on top of die attrition error (CW 4/14/14)
- On out-of-collar strikes (rare) (CW 11/25/19, 11/21/22)
Rim-restricted design duplication (form of machine doubling) (CW 10/6/03, 2/22/10, 5/24/10, 12/6/10, 5/13/13, 12/30/13, 3/8/21, 4/12/21)
-
- 2004 cent (ES March/April 2007; CW 2/22/10)
- 1994 cents (CW 5/24/10, 8/22/11)
- 1981-P quarter and 1979-D dime (CW 12/30/13)
- Presidential dollars (ES Sept/Oct 2007; CW 2/22/10, 12/6/10)
- Foreign coins (CW 2/22/10)
- On face struck by anvil die (CW 10/21/13, 7/20/20)
- Bifacial (CW 7/20/20)
- In conjunction with push doubling (CW 12/6/10, 7/20/20)
Ejection Doubling (CW 11/7/22)
Skidding Die Errors (CW 8/15/16, 11/27/17)
-
- Design decapitation error (top of design scraped off)
- Slide doubling (see Machine Doubling)
- Design ablation error (design scraped off by die movement on 2nd strike) (ES March/April 2008, Jan/Feb 2011; CW 9/13/10)
- Combined with tilted die (CW 9/27/21)
- From broken die (CW 7/26/21)
- Skidding misalignment
- Two-stage (CW 4/13/20)
One-sided double-strikes (ES March/April 2000, Jan/Feb 2002, July/August 2003)
-
- Hammer die rotated (CW 11/29/10)
- Instantaneous
- Gradual
- Hammer die misaligned (CW 5/19/08, 5/3/11, 9/9/13, 3/8/21, 4/24/23)
- Instantaneous
- Gradual
- Anvil die misaligned (CW 9/9/13, 8/31/20)
- Anvil die rotated (at least one known example, a proof Kennedy half dollar)
- Rotated, with rocking die (CW 5/25/20)
- False one-sided double strikes (CW 11/29/10)
- Hammer die rotated (CW 11/29/10)
Flat Field Doubling (imperfectly aligned proof strikes) (CW 4/29/13)
Off-center strikes
-
- Cupped off-center strikes
- With collar scar
- Without collar scar
- Uniface strikes
- Stretch strikes
- Uniface
- Die struck on both faces (covered under high pressure strikes)
- With unexplained, flat dent at opposite pole (not a “sideneck strike”)
- Cupped off-center strikes
Chain strikes (CW 4/12/10)
-
- Normal chain strikes with straight edge
- External chain strikes (ES Jan/Feb 2003)
- Concave, convex, sinuous, and irregular chain strikes (ES Jan/Feb 2001, July/August 2002; CW 4/12/10)
Foreign Object Chain Strike (CW 5/25/15)
-
- Chain strike against feeder
Machine Part Impingement (CW 5/25/15)
-
- Bilateral
- Unilateral
Saddle (Tandem) Strikes (CW 6/27/11)
-
- Hump present
- Hump absent
- Inverted hump (hump points toward reverse die) (CW 9/19/16)
- Buckling toward anvil die
- Due to inverted die setup
- Die position
- Head-to-head
- Head-to-base (early to mid- ’70s, mainly)
- Face-to-back
- Other orientations
- Gap between adjacent dies
- Narrow
- Wide
- With inverted die installation
- Sideneck strikes (“one-die saddles”) (Expanding planchet collides with side of die neck) (CW 5/30/11)
- On quarter dollars (CW 12/9/19)
- (covered under collar deployment errors)
Split Plating Doubling
Foldover Strikes (ES July/August 2007; CW 10/10/05, 8/15/11, 1/30/12, 9/15/14)
-
- Out-of-collar
- In-collar
- With edge strike persisting
- On struck cents (normal and error)
- Double foldover strikes (“Z-fold”)
- Axial fold
- Paraxial fold
- Inward fold
- Outward fold
Edge Strikes (CW 7/18/11, 10/12/15, 3/1/21)
Extrusion strikes (an effect, not an independent error) (ES March/April 2004; CW 10/24/11, 1/15/18)
-
- With indent or partial brockage
- Between two indents or partial brockages
- With struck-through error
- Struck through clipped planchet
- With retained cud
Multiple strikes (CW 3/30/15)
-
- On-center/Off-center
- In-collar/out-of-collar
- Flipover
- Numerous closely-spaced strikes (ES Nov/Dec 2004; CW 1/11/21)
- Involving second die pair
- Delayed second strikes (ES July/August 2007; CW 1/9/12, 6/13/16, 6/6/22, 1/23/23)
- Dual-date double strikes (CW 6/13/16)
- Proof double strikes (CW 9/19/22)
Indents
-
- In-collar/out-of-collar
- Partial
- Full (CW 7/30/12)
- Centered
- Uncentered
- “Internal” indents (CW 11/1/10, 2/28/16)
- On obverse
- On reverse
- Multiple indents
- Irregular indents
- Produced by error coins
- Produced by clipped planchet
- Unexpectedly shallow indents (CW 12/28/20)
- Indent by smaller planchet (CW 5/19/08)
- External disc impressions (CW 3/18/19)
Brockages
-
- Full
- Centered
- Uncentered
- Rotated (relative to die-struck design on opposite face)
- Partial
- Conventional
- Aligned partial brockage (ES May/June 2005; CW 1/17/11, 12/5/22)
- From partial die cap
- From elliptical clip coin
- From elliptical strike clip
- Internal partial brockage (CW 11/1/10)
- In-collar/out-of-collar
- From another denomination (ES May/June 2005; CW 8/1/21)
- From another error coin
- From wrong planchet error (CW 11/28/22, 6/12/23)
- From mangled and crumpled coins (often multi-struck) (CW 10/2/23)
- From weakly-struck coins (CW 11/20/23)
- Flipover brockage (CW 4/23/12)
- On obverse
- On reverse
- First-strike brockage
- “Mirror” brockage (unexpanded, undistorted) (CW 6/13/11, 3/17/14, 5/6/19, 10/28/19, 7/11/22, 6/27/22, 4/10/23)
- Distorted first-strike brockages
- Mid-stage and late-stage brockages
- By struck fragment (CW 6/11/12)
- Aligned with opposite, die-struck design
- Not aligned with opposite design
- From struck die fill (very rare) (CW 8/20/18)
- From thin pieces of metal (CW 7/23/18)
- From large dropped filling (CW 5/13/19)
- Multiple brockages (CW 9/26/11)
- From multiple strikes
- From clashed cap
- From multi-struck coin (CW 7/4/22)
- From more than one coin in striking chamber
- From coin trapped between die cap and planchet
- Clashed cap strikes (CW 8/30/10, 11/21/11, 1/13/14)
- From a late-stage die cap that clashed with the opposite die
- From a uniface die cap that clashed with the opposite die
- From an early-stage die cap that clashed with the opposite die
- From a cap that was striking counterbrockages that clashed with the opposite die
- From a flipover die cap that clashed with the opposite die (CW 1/13/14)
- Full
Counterbrockages
-
- Full (CW 10/11/10)
- Partial (CW 11/8/10)
- In-collar/out-of-collar
- Counterbrockage of obverse on obverse
- Counterbrockage of reverse on reverse
- Flipover counterbrockage (CW 4/19/21)
- Early, middle, and late-stage counterbrockages
- From another error coin
- Brockage-counterbrockage combination (8 types) (ES Nov/Dec 2009; CW 11/12/12)
- Multiple counterbrockages (ES March/April 2010)
- On second strike
- Rebound counterbrockage (always on 3rd strike) (CW 11/9/15)
- Secondary counterbrockage (CW 4/19/21)
- Grease-generated counterbrockage (CW 4/11/22)
Horizontal lipping (CW 11/30/15)
-
- In conjunction with in-collar indents, partial brockages, and struck-through errors
Die caps (CW 8/6/13, 1/7/20)
-
- Hammer die caps (usually the obverse die)
- Raised design on working face
- Brockage on working face
- Uniface die caps
- Complex die caps
- Anvil die caps (usually the reverse die)
- Cupped toward anvil die, hammer die, both dies at opposite poles, or expanded in the horizontal plane
- Partial (off-center) die caps (hammer or anvil) (CW 1/17/11)
- With cupping
- Without cupping
- Detached cap bottoms (ES March/April 2001, May/June 2001)
- Clashed caps (CW 1/22/24)
- Hammer die caps (usually the obverse die)
Capped die strikes (generic — without identifiable images)
-
- Struck by uniface die cap
- Struck through late-stage die cap
- Struck through cap-like obstruction
- Struck through split or torn cap
- Proportional de-expansion (both faces struck through die cap or cap-like obstruction) (CW 11/11/13, 5/28/18)
Struck by impaled die cap (CW 6/10/13)
Capped die doubling (doubling associated with capped die strikes) (ES Sept/Oct 2005; CW 6/18/12, 5/16/22)
-
- Shifted/rotated cap strikes (ES May/June 2000, March/April 2012; CW 11/21/11)
- Correctly-facing incuse design elements (CW 11/3/08, 6/28/10, 6/11/12, 10/19/15, 8/12/19, 10/23/23, 11/13/23)
- Multiple sets due to several preceding shift-and strike event
- Correctly-facing incuse design elements (CW 11/3/08, 6/28/10, 6/11/12, 10/19/15, 8/12/19, 10/23/23, 11/13/23)
- Unexplained, close raised doubling
- Expansion ripples
- Incuse doubling surrounding raised elements (CW 8/24/20)
- Shifted/rotated cap strikes (ES May/June 2000, March/April 2012; CW 11/21/11)
“Struck-through” errors
-
- Struck through fragment
- Struck through clipped planchet (ES Sept/Oct 2002; CW 8/25/14)
- Struck through thin struck fragment (CW 6/11/12)
- Face-up (correctly-facing incuse design elements)
- Face-down (mirror-image design elements)
- Trapped between planchet and opposite die (mirror-image design elements)
- Struck through detached lamination flake (CW 2/7/05, 6/11/12)
- Struck through clad layer
- Clad layer unstruck
- Clad layer previously struck
- Struck through reeding (CW 11/14/16, 8/21/23)
- Struck through split planchet
- Obverse
- Reverse
- Struck through hardware (bolts, screws, washers, etc) (CW 3/7/11)
- Struck through feeder (ES Nov/Dec 2005; CW 3/7/11)
- Struck-through unidentified machine part (CW 3/7/11)
- Struck through emery disc (CW 12/16/02)
- 1986 Silver Eagles struck through emery disc (CW 12/16/02)
- Struck through “grease” (die fill)
- Assorted ingredients, textures, viscosities, and consistencies (smooth, coarse, stiff, viscous, etc.)
- “Greasy ghosts” (ghost images from grease accumulations) (CW 7/5/10, 7/10/17)
- Grease-mold doubling (ES March/April 2006, July/August 2006, Nov/Dec 2008; CW 8/19/13, 10/20/14)
- Grease-mediated radial smear (CW 7/31/17)
- “Spackled dies” (intentionally applied grease) (CW 10/18/21)
- Bifacial (5/22/23)
- Filled dies
- Single design element (CW 6/29/20)
- Multiple design elements
- Struck through bulging die filling (CW 1/16/17, 5/20/19)
- Filled collar/obstructed collar (ES Jan/Feb 2006; CW 9/22/14)
- With flange
- Surface Film Effects (ES May/June 2003; CW 8/16/10, 6/11/12, 10/29/12)
- Surface film doubling
- Surface film afterimage
- Surface film transfer
- Surface film transfer with clash marks
- Dropped fillings (ES May/June 2003; CW 8/16/10, 6/11/12, 10/29/12)
- Isolated elements (dropped letter, dropped number) (CW 2/7/05)
- Conjoined dropped fillings (CW 8/16/10)
- Large, multi-element dropped fillings (CW 4/19/10, 8/16/10, 11/14/22)
- Retained dropped fillings
- Struck through floating encrustation (on second strike) (CW 1/18/16, 6/18/18)
- Yanked-out fillings (CW 1/16/23)
- Struck through miscellaneous foreign matter
- Metal dust, shavings
- Cloth (CW 5/14/12, 12/3/18, 9/26/22)
- String (CW 3/9/20)
- Wire
- Field-restricted struck-through errors (CW 11/18/13)
- Split or torn in two by struck-thru object (ES Nov/Dec 2007; CW 3/7/11, 7/13/15)
- Retained struck-through errors (struck-in errors) (CW 7/18/16, 1/25/21, 9/13/21)
- Embedded dropped filling (see above)
- Embedded die fill (shapeless)
- Die fragment (CW 2/6/23, 3/13/23)
- Scrap metal
- “Staple” (bristle from wire brush)
- Plastic (associated with bullion coins)
- Metal foil
- (Cu-Ni)? associated with dimes and nickels)
- Copper foil (ES Nov/Dec 2007)
- Rubbery material (from die cover?)
Uniface strike (cross-classified with indents) (CW 7/30/12, 9/16/19)
- In-collar (CW 12/5/22)
- On second strike (CW 11/29/10, 9/16/19, 6/5/23)
- “Augmented” in-collar uniface strikes (CW 9/14/20)
- Out-of-collar
- Centered
- Off-center
- Out-of-collar
Sandwich strike (coin struck between two coins or planchets) (CW 5/16/11, 10/31/16, 11/20/17, 5/28/18, 3/22/21)
-
- Partial
- Full
- Between two struck coins
- Between two planchets
- Between a coin and a planchet
- Between struck coin and obverse die cap
- Between obverse and reverse die cap
Nested coins (CW 3/16/20)
Mated pairs (CW 11/9/20)
Bonded coins
-
- Pile-ups (clusters)
Strike clips (ES July/Aug 1999, May/June 2001; CW 6/15/15)
-
- Vertical shear clips (V)
- Sheared between die and collar alone
- Sheared between collar and overlying planchet
- Horizontal shear clips (H)
- Tensile strike clips (T)
- Concave strike clips (V, H, T)
- Elliptical strike clips (V, H, T) (CW 4/5/10, 12/5/22)
- Straight strike clips (H)
- Saddle strike/strike clips (H)
- Vertical shear clips (V)
Detached reeding
-
- From forced broadstrikes
- From stiff collar
- Torn-off fin
Coin shrapnel (“breakaway fragments”)
-
- Angular
- Crescentic
- Oval
- Circular or sub-circular
- Semilunar
- Irregular
Intra-Strike Damage (damage coincident with strike) (CW 5/30/2011, 12/20/21)
-
- Flat contact facet at 6:00 opposite off-center strike
- Machine part impingement on unstruck portion of off-center coin (CW 5/25/15)
- Ejection damage to edge of unstruck perimeter.
- External struck-through errors (with cupping) (CW 3/25/19)
- Concave damage opposite off-center strike (CW 12/30/19)
Cupping (CW 12/7/09)
-
- With and without collar scar
- In a single strike
- Associated with multiple strikes
- With die caps
- Cupping toward hammer die
- Cupping toward anvil die
- Expansion in horizontal plane
- On unobstructed strikes (CW 3/18/19)
- Spontaneous
- Forced
-
- By stiff collar
- By outlying disc of coin metal
- By foreign metal or machine part
-
Impact-Induced Warping (CW 3/16/15, 1/13/20)
Malrotation Errors (multi-sides coins only) (CW 3/23/15, 11/8/21)
Proof edge lettering errors (generated during strike by segmental collar)
-
- Weak edge design due to segmented collar not closing fully (wide seams)
- Segments arranged in incorrect sequence (see Die Installation Errors) (CW 4/7/08)
Part VII. Post-Strike Mint Modifications
Edge lettering applied after strike (incuse) (small dollar coins)
-
- Absent lettering (CW 4/26/10)
- Due to bypassing the lettering device
- Due to excessive spacing between steel wheel and lettering die
- Vertically misaligned letters (cut off at top)
- Vertically misaligned letters (cut off at bottom)
- Wrong spacing between incuse design elements
- Obliquely-oriented lettering
- Overlapping letters
- Two sets of letters
- Skipped letters
- Letters on wrong planchet
- 2007-D Sacagawea dollar with Presidential edge lettering (CW 7/9/12)
- Chipped letter
- Lightly impressed letters (weak lettering) (CW 4/26/10)
- Unusually deep letters (coin squeezed too hard, leaving a rippled margin)
- Incomplete letters
- Smeared letters
- Edge letter font subtypes (CW 10/18/10)
- Wrong date on edge (doesn’t match any President of that year) (CW 2/22/10, 3/1/10)
- 2009 Zachary Taylor dollar with 2010-D edge inscription (CW 2/22/10, 3/1/10)
- Edge lettering on unstruck planchet (CW 3/26/07, 3/17/08)
- Lettering die inclusion (CW 9/14/15)
- Absent lettering (CW 4/26/10)
Note: Edge lettering and other edge design elements may be impressed during upsetting, during the strike, by a special machine before the strike, or by a lettering device after the strike. Similar-looking defects can occur in each of these processes. Any edge design that forms a closed interlock between the edge of the coin and the collar cannot be produced during the strike since that will prevent ejection of the coin after the strike.
Special Note: Some presidential dollar coins have had the edge lettering removed outside the mint. Use caution when buying any edge lettering error.
The diagnostics for authentic presidential coin missing its edge lettering are as follows:
1. Diameter should be 26.46 mm. Coins altered outside the mint will have a diameter that is less than 26.46 mm and will have a diameter of approximately 26.21 mm.
2. The coin’s weight should be approximately 7.98 g ± .03 g. Altered coins will weigh less from the removal of the edge lettering. Weights of approximately 7.89 g are commonly seen on altered coins.
3. An unaltered presidential dollar coin will have vertical lines along the edge. These lines are created when the coin is ejected. Altered coins will not normally have these lines, but instead will have horizontal lines. These horizontal lines are from milling or similar machines used outside the mint to remove the letters and are the aftereffects of the metal being abraded off the coin.
The above image shows the vertical lines present on the edge of an unaltered presidential dollar coin with no edge lettering
Table of edge lettering errors found on the presidential and native American dollar coins
Post-strike chemical treatment
Matte or frosted finish applied after strike
-
- Finish omitted on one or both faces (CW 8/1/11, 8/29/11)
Part VIII. Post-Strike Striking Chamber Mishaps
Post-strike die contact
- Ejection impact doubling (post-strike design transfer from die) (ES Jan/Feb 2005; CW 8/1/05, 8/29/05, 2/25/13, 2/26/18, 4/9/18, 10/8/18, 4/12/21)
Ejection damage
- Crenellated rim (CW 10/23/17)
- Feeder/ejector scrapes on coin (CW 3/19/18, 3/7/22)
Part IX. Post-Strike Mint Damage
Illicitly applied die impressions (CW 11/16/20, 1/4/21, 2/1/21, 8/29/22)
Pseudobrockage (false brockage) (ES Nov/Dec 1999; CW 8/23/10)
Fused coins
Rolled and squeezed
Accidentally resized
Other (folded, crushed, scraped, bent, etc.)
Intentional damage (e.g., canceled, waffled)
Zinc deterioration on copper plated Lincoln cents
Part X. Wastebasket/Composite Categories
Ghost images (CW 8/1/11)
-
- Progressive, indirect design transfer (a.k.a. internal metal displacement phenomenon, ghosting, heavy design transfer) (CW 6/7/10)
- Worn clash marks
- Thin planchet (CW 8/2/10)
- Split planchet (CW 8/31/15)
- Split-before-strike (CW 8/2/10)
- Split after-strike
- Coin thinned by strike(s)
- Weak strike (CW 4/11/11)
- High pressure strike
- “Greasy ghost” (CW 7/5/10)
- Surface film afterimage (CW 5/2/11)
- Surface film transfer (CW 5/2/11)
- Split plating afterimage (CW 5/2/11)
- Coarsened crystallite afterimage (CW 5/2/11)
- Slide zone ghost letters (? 11/16/15)
- Incuse ghost images associated with capped die strikes (CW 10/25/21)
Doubling
-
- Die Deterioration Doubling
- Raised
- Incuse
- Machine Doubling
- Stutter strikes (3 types)
- “Abrasion doubling” (extremely doubtful) (CW 7/15/13)
- Split plating doubling (CW 3/26/12)
- Surface film doubling
- Grease-mold doubling (CW 8/19/13)
- Longacre doubling
- Offset laser-etched frosting on proof dies (CW 2/21/11)
- Plating disturbance doubling (CW 3/28/11)
- Flat-field doubling (imperfectly aligned proof strikes (CW 4/29/13)
- Die Deterioration Doubling
Embedded matter (CW 12/14/09)
-
- Poured-in
- Slag
- Intrinsic metallic inclusion
- Rolled-in
- Punched-in (by blanking die)
- Squeezed-in (upset mill inclusion) (CW 9/6/10)
- Scraped-in (CW 2/23/15)
- Struck-in
- Lettering die inclusion (CW 9/14/15)
- Poured-in
Edge overhangs (CW 11/30/2015)
-
- Partial collar errors
- Horizontal lipping
- Stiff collar errors
- Forced broadstrikes
Part XI. Non Errors:
Counterfeit Coins
-
- All strikes from counterfeit dies
- First strike authentic; later strikes counterfeit
- Counterfeit strike on authentic planchet
- Counterfeit strike on counterfeit planchet
Fabricated or Altered Errors
-
- Acid Damage
- Planchet clips made outside the mint
- Plated Coins
- Counterfeit Dies
- Solder on coins
- “Squeeze Job” or “Vise Job” or “Garage Job”
- De-plated Coins (Chemically or Electrolysis stripped)
- Dryer Coins
- Coins that are rolled and squeezed in the horizontal plane
- Spooned coins
- Pinpoint alterations (date, mintmark)
- Glue
- Holed coins
- Snipped-off and crimped edges
- Heat damage (blisters, discoloration)
- Rippled coins
- Texas coins
Damaged Coins
-
- Chemical corrosion
- Environmental discoloration and corrosion
- Crushed
- Bent
- Impact damage
- Stacked coins crushed and fused in equipment
Enhanced Errors (genuine errors subsequently altered to look more exotic)
The End of the Check List
Overdate / Repunching or Re-engraving the Date
PART II. Die Varieties:
Overdates
Definition: An overdate is a modification made to a working hub that involves two different numerals being punched or engraved into the same spot. One or more digits may be affected. Overdates sometimes represent an attempt to correct a mistake when the wrong punch was initially used to punch in a digit. At other times it represents an expedient measure. Dies left over from the previous year may simply have one or several digits repunched so that the die can be used in the current year. The relevant area of the die face is often abraded so that the prominence of the original date is reduced.
Overdates are closely related to re-punched dates. However, a re-punched date doesn’t involve the superimposition of one digit over a different digit. Repunched dates simply involve the repunching of the same digit or digits.
Overdates should not be confused with Class III doubled dies (design hub doubling). Although the outcome looks similar, the nature of the variety is entirely different.
Overdates ceased being a possibility for U.S. coins in 1909 when the mint began placing an engraved date on the master die.
The image below shows an 1892 Peruvian 1/2 dino, with a repunched 9 over an underlying 8.
Centrally Located Doubling
PART II. Die Varieties:
Doubled Die:
Single Squeeze Hubbing:
Centrally-located doubling
Definition: The majority of centrally-located doubled dies are generated by the single-squeeze method of hubbing. During the single- squeeze process, two mishaps may occur. Sometimes a slightly tilted hub (or die) will settle spasmodically, causing a “skip” that will generate a secondary image. At other times a technician will interrupt a hubbing in its early stages in order to re-position the hub or the die. When the hubbing is restarted, this
may result in offset impressions. This is not inevitable, however, as the second hubbing may obliterate the impression left by the first hubbing.
The following images (top left and right) depict some centrally-located doubled dies seen on the 2009(FY) Lincoln cent reverse die.
Class I
Part II. Die Varieties:
Doubled Dies:
Class I (Rotated Hub Doubling):
This class of doubled die is probably the easiest to conceptualize and diagnose. It emerges from two separate hubbings. Prior to the second hubbing, the working hub or the working die rotates around its vertical axis (the axis that passes though the center of the hub/die face). Class I doubled dies are listed as showing a clockwise (CW) or counter-clockwise (CCW) rotation. The direction is determined by which hubbing is clearest and most complete. This is usually the second hubbing (which tends to be deepest). Exceptions do exist, however.
Doubling typically has a rounded appearance. When the hubbing impressions are extremely close, the doubled die may only be recognizable from notched serifs and corners, subtle separation lines, or extra thickness.
Below is an overlay diagram of a fictitious Class I doubled die that has a clockwise rotation similar to the King of Doubled Dies, the 1955P DDO-001. Notice how the spread is equal on all devices and increases the farther out you go from the center of the coin. DDO refers to a doubled die that affects the obverse face of a coin. DDR refers to a doubled die that affects the reverse face of a coin.
Below are photos of 1972P DDO-001, a Class I DDO with a strong CW spread on all outlying devices and parts of the jacket. A second hubbing typically eliminates interior parts of the design produced by the first hubbing. Therefore doubling is often only detectable in areas bordering the field. Here, only the outside elements of the portrait of Lincoln and the motto show doubling while the centrally-located details are lost to the second hubbing.
Hubbings are ordered from lightest to deepest, either CW or CCW. On the G of GOD you can see that the heavier of the duplicate letters (G-2) is located to the right (clockwise) of the lighter letter (G-1). It is likely that the heavier letter represents the second hubbing, but this cannot be proven.
Below you can see clear separation between the letters of TRUST. On the first few digits of the date, where design elements are more closely bunched (due to being closer to the center of the design), distinct notching can be seen at the upper and lower corners of numeral 1.
Below is a Class I doubled die on the reverse face of a 1964 cent ( 1964P DDR-001). It shows a counterclockwise (CCW) spread. Again there is clear separation, notching, and rounded doubling. The doubling is strongest in “STATES oF” due to the axis of rotation being located slightly south of center.
The next example is a DDR on a 1979 Israeli 25 agorot. The spread, best seen in the Hebrew letters located near k12, is elsewhere indicated by notches and subtle separation lines. As would be expected of any Class I doubled die, the doubling is weakest toward the center and strongest toward the perimeter of the coin.
Notching of corners and serifs reflects the presence of closely-spaced letters and numbers. Often there is a difference in height as well between the closely overlapping design elements. Below is a 1934-D quarter listed as DDO-001 that shows very obvious stepped notching in IN GOD WE TRUST. Subtle doubling, also in the form of notching, is evident on all the peripheral design elements. Detailed photos presented below depict notching in the E of LIBERTY, as well as the 3 of the date.
NOTCHES EXPLAINED:
If a die shows hub doubling and there is a rotational shift, the notches will be more apparent. The following illustrations show a hypothetical CCW rotation with Red being the first hubbing and Green the second. The green letters are also slightly south (or down) in relation to the red. While the spread is minor, the notches are obvious. Rounded portions of letters (like the o and S) show the development of a secondary, offset ellipse.
Now we will see a stronger CCW spread where there is very little degree of offset between the hubbings. The result is fewer notches overall, but where the design drops off, such as the serifs on the S or the top of the A, there will be
minor notching or splits. Below are some notching diagrams that will give you an idea of where Class I (and also Class V) hub doubling can produce notches.
Below are examples of Class I Doubled Dies on various Lincoln cents. 1941 DDO-001
1941 DDO-002
1936 DDO-001
1971 DDO-002
On to CLASS II
All doubled die illustrations are by Jason Cuvelier
Class II
Part II. Die Varieties:
Doubled Dies:
Class II
The next class, Class II, is harder to find empirical evidence to conclusively prove the cause of the Hub Doubling. Most often hypothesized as a misalignment event relating to either the Die or the Hub, which has expanded or contracted too much in relation to the first hubbing during the annealing or tempering processes.
Class II is characterized by having a spread along the outside devices from deepest to lightest hubbings, which goes toward the Center (C) or towards the Edge (E).
Dies are annealed (cooled slowly) to make them softer so they are more susceptible to taking an impression of the Hub. The Hub in contrast is tempered, quickly cooled, so that it is more durable and does not distort while transferring an image to the Die. If for whatever reason, either the Die or the Hub were not to return to its normal size in between hubbings, doubling could result like the illustration below of a fictitious 1960 Lincoln cent where doubling would be more pronounced toward the rims.
There is a large number of other Class II DDRs on the Lincoln cent from 1962 through 1964.
Here we can see a Jefferson nickel listed as 1962P DDR-015 (15-R-II-C) with a medium spread on the reverse that is visible on most devices. The doubling is more pronounced near the rim and gradually decreases as we navigate toward the center. Notice how light the spread becomes on FIVE and the beginning of MONTICELLO.
On to CLASS III
All doubled die illustrations are by Jason Cuvelier
Class III
Part II. Die Varieties:
Doubled Dies:
Class III (Design Hub Doubling)
Likely the easiest Doubled Die to explain yet the least common to have occurred. Class III Doubled Dies occur when after the first hubbing with one design another hubbing follows of a different design or a slightly altered design.
Below is an overlay diagram of a fictitious Class III Doubled Die that is similar to several Doubled Dies that occurred during 1960 when the Mint used two different Master Dies, the first bearing a small date, then another made later that year, bearing a larger date. You can see clear doubling in the date and then slight doubling in LIBERTY.
Doubling is sometimes the least dramatic characteristic observed, as in some cases with other denominations, such as on a Mercury Dime with a 1942 over a 194. Designated as 1942P DDO-001 (FS-10.7 [101] when, for whatever reason, a die after having been hubbed with a 1941 hub, was hubbed a second time with a hub having a 1942. There is some doubling in IGWT, but there is a very dramatic, naked eye obvious, overdate. It is important to note that all overdates after 1907 are Doubled Dies whereas previous overdates had dates punched into the die one on top
of the other.
Collectors of Lincoln cents should have an easy time understanding what would happen if a 1960 small date hub and a 1960 large date hub were both used to create a die. There are four cases of this happening, three on proofs and one business strike from Denver (which also has a nice RPM). Below is an approximation overlay of a small date over a large date with an example designated as 1960P DDO-002 (FS-102). The doubling is very obvious in the date, LIBERTY and parts of IGWT. At the bottom the small date is lavender while the large is green; the first shows a small over a large and the second shows a large over a small. They almost line up perfectly with DDO-002.
The 1960 Denver version is just as dramatic in the date but less so in LIBERTY. The small date almost looks as if it were placed on top of the large date. Listed as 1960D DDO-001 & RPM-100 and is illustrated below. John Wexler states (The Cherrypicker’s Guide to Rare Die Varieties, 4th edition, volume one, 2001) that in the “early days” any Doubled Die that “…did not fit the parameters of any of the other classes of doubling” were often erroneously designated as a Class III Doubled Die. Wexler also says that “[he] will not assign a Class III designation to a variety unless [he] has documented evidence that different designs were in use [that] year….”
Another curious set of examples comes from 1949 when, for reasons unknown, three dies were hubbed with a pointed topped 4 hub and then hubbed again with a blunt topped 4. They are listed as 1949S DDO-001, 002 &003 by CONECA. It has been hypothesized that the pointed hub is that from 1948 which was absent an 8 digit (or the 8 was removed). Below is DDO-002 and then an approximation overlay showing a pointed 4 (red) from 1948 undera blunt 4 (green) from 1949. They match up convincingly and suggest the likeliest, but not necessarily the only possible explanation. As a suggested reason for this (BJ Neff) proposed the possibility that the Mint was short on hubs and quickly altered an extra 1948. What isn’t answerable is why only three were hubbed once using this particular hub.
Next is an overdate Jefferson nickel, listed by CONECA as DDO-003 (3-O-II-C+III+V-CW) and in the CPG as FS-05-1943P-101 (28). Here we have a situation where a lighter hubbing of a ‘42 is partly concealed by a deeper hubbing of a ‘43. To clarify, below is a 1943 Jefferson overlaid with a 1942; the diagonal line matches part of the primary curve of the 2, while the little protruding point below the curve of the 3, matches the corner of the bottom of the 2.
Finally, a comparison illustration of the four known 1960 P & D Class III doubled dies.
On to CLASS IV
All doubled die illustrations are by Jason Cuvelier
Class IV
Part II. Die Varieties:
Doubled Dies:
Class IV (Offset Hub Doubling)
This class of Doubled Die is produced when two hubbings have their centers misaligned. It is characterized as having doubling that is evenly spread in one direction. The doubling is unlike that found on Classes I or V, where the misalignment-event shows a rotation at or near the center (I) or at or near the rim (V). Doubling is often rounded, found closer to the center, and when identified on numeric or alphabetic characters, shows notching.
It has been hypothesized that the reason many examples do not show doubling near the rim is because one of the hubbings only received an uncharacteristically incomplete hubbing. Such an incomplete hubbing would result in design elements not being pressed deep enough in the middle of the die, and not at all along the perimeters. The die originates in a conical shape until it is completely pressed down, if the incomplete hubbing was the first, the outer devices may not have been hubbed the first time around.
Below is a facsimile of a fictitious 1960P with a strongly doubled Class IV DDO. In this case the first hubbing would have been centered and complete, with the second hubbing having its center oriented N-NE from the first. It should be noted that this example is showing universal doubling on all design elements (including the whole portrait) which has never been documented but shown for effect.
Below is 1983 DDR-001, which exhibits a large spread going North, it is stronger than the above hypothetical illustration. The ’83 DDR shows strong peripheral doubling. The central elements show some doubling around the parameter of the memorial and in a few sections of the building itself (like the upper portions of the columns). Notice the notching (a clear indication of hub doubling), rounded secondary images and how the deeper hubbing shifts consistently in one direction from the lighter hubbing.
On to CLASS V
All doubled die illustrations are by Jason Cuvelier
Class V
Part II. Die Varieties:
Doubled Dies:
Class V (Pivoted Hub Doubling)
Class V Doubled Dies are related to Class I Doubled Dies as they both have a rotation in the doubling. If one understands Class I, Rotated Hub Doubling, then understanding Pivoted Hub Doubling should be a snap. Where Pivoted hub doubling differs is that the center of rotation is very near or at the rim. (While Rotated hub doubling may not always be dead center, nevertheless, as long as it is in the central area, it is considered Class I whereas anything near the rim is Class V.)
Like Rotated hub doubling, doubling is either Clockwise (CW) or Counter-clockwise (CCW). Unlike Rotated hub doubling, the degree of rotation (or the spread) is strongest opposite the pivot point. Doubling progressively diminishes from there as you move toward the pivot point. Rotated hub doubling, by contrast, shows same degree of rotation all away around.
Below is a facsimile of a fictitious 1960P DDO with Class V doubling. The pivot point is in-between coordinates K5 and K4 near the date. A K(number) represents an area along the rim that coincides with numbers on a clock. Notice how there is no doubling at the date, but directly opposite the pivot point at K10.5, there is very strong doubling. Follow the doubling around and it gradually decreases.
A similar DDO to the illustration above is 1995 DDO-001 (FS-101). It has its pivot point near K4 and shows strong CW doubling in IN GOD and parts of LIBERTY with lesser doubling in WE TRUST.
For clarity, below is another facsimile of a fictitious DDO also with a K4 pivot point like that of the 1995 above. The hubbings are colored green (lightest) and red (deepest). The strongest doubling is seen in LIBERTY and IN, as you move away toward the date doubling decreases.
For comparison a shot of LIBERTY from 1995 DDO-001 is next to an overlay from the above hypothetical. Below are details of 1995 DDO-001.
1936 DDO-003 (FS-103) with a pivot point at K5 shows a strong spread in IN GOD that progressively decreases toward TRUST and cannot be seen in the date.
Next is 1980 DDO-001 (FS-101) with a K11 pivot point showing strong doubling in the date, decreasing in LIBERTY and not at all in the motto.
1966 DDO-001 (FS-101) with pivot point at K7 shows strongest in TRUST and fades but is visible in the date, WE, the eyelid and edge Lincoln’s coat.
1973 DDO-001 has a pivot point around K5. Doubling is seen in LIBE and IN TRUST.
1995-D DDO-003 (FS-101) with a pivot point at K7.5 shows the strongest doubling in TRUST. Doubling diminishes through the rest of the motto and date. Some doubling is visible in the hair, ear, eyelid and mintmark. The mintmark is part of the design (not punched into the die) so this is not an RPM.
On to CLASS VI
All doubled die illustrations are by Jason Cuvelier.
Class VI
Part II. Die Varieties:
Doubled Dies:
Class VI
Class VI: Distended Hub Doubling occurs during hubbing and is related to lateral expansion of the die face. Expansion is impeded in areas where the raised elements on the face of the working hub interlock with the freshly-penetrated die face. This causes distortion in elements that are relatively near the perimeter of the die face. The affected elements are thickened, and may show sloping, pointed, or twisted regions.
Historically Class VI has been attributed to a worn-out hub that becomes distended from extended use. However, if that were the case we should see an even progression of design distortion and expansion in any year with a Class VI doubled die. In other words, we should encounter specimens in which the affected design elements show slight to marked expansion. This has not been the case. Another problematic association is the tendency for Class VI to be present with Class II (Distorted Hub Doubling). If Class II can be traced to faulty annealing of the die, why would it be found so routinely with Class VI if the two do not share a common cause or even a related cause?
Class VI in all likelihood has the same root cause as Class II – a problem intrinsic to the die steel or one that is caused (or exacerbated) by faulty heat treatment. During annealing the die face experiences excessive expansion, sometimes localized and sometimes over the entire die face. The difference between the two forms of hub doubling is the location and the timing of the expansion. A Class II die (or hub) will expand right after the first hubbing, distorting the perimeter and pushing it beyond the intended circumference. A Class VI by contrast will expand during the first or second hubbing from the heat generated by the hubbing.
In a Class VI doubled die, affected devices are in partly or entirely parallel to the design rim. During the hubbing, the die face experiences lateral expansion, but the hub will not. Any raised part of the hub, such as letters or the design rim, will inhibit expansion. As a result, the die steel twists away from or flows around the stationary devices on the hub and toward the rim. Whenever a raised device from the hub lies in the path of the expansion, it will inhibit that expansion. The design rim too is raised and will also curtail expansion nearest the perimeter