Die Clash
Photo: Wcarper · CC BY 1.0 via Wikimedia Commons · Close-up of a 1993 Lincoln cent with a misaligned die clash (MAD clash): incuse ghost outline from the reverse die visible in the field left of the date, marked with annotation arrows by the photographer. Alternative without arrows (subtler error): Smithsonian's File:1831-5C (clashed rev die) (rev).jpg, public domain.
What it is
If the press cycles without a planchet in place, the obverse and reverse dies smash directly into each other under full striking pressure. Each die picks up a faint mirror impression of the other die's design. Every coin struck afterward then shows ghostly outlines of the opposite side's design in its open areas — for example, faint columns of the Lincoln Memorial visible around Lincoln's portrait. The ghost images are always in the exact same position, because they're part of the die now, and they slowly fade as the mint polishes the dies or they wear.
How to spot it
Study the open field areas of the coin under good angled light with a loupe. Look for faint raised outlines that don't belong to that side's design, and match them against the other side: rotate the coin and check whether the ghost lines up as a mirror image of the reverse (or obverse) design. Classic clash zones are around the portrait and in front of the face. The marks are smooth, shallow, and raised, not scratched in.
What it's worth
Light clashes add little, $1-$10. Strong, dramatic clashes bring $10-$50 on modern coins, and famous named clashes on classic series (like Morgan dollar VAM clashes or the 'Bugs Bunny' Franklin half, where clash marks give Franklin buck teeth) carry solid collector premiums of $25-$200+.
Famous examples
- 1955 'Bugs Bunny' Franklin Half Dollar
- Morgan Dollar VAM clashed dies
- Clashed-die Lincoln Memorial Cents
Documented varieties with this error
Series where this error is found
Flying Eagle Memorial Cent Buffalo Nickel Mercury Dime Roosevelt Dime Franklin Half Kennedy Half Morgan