Die Cracks
As dies are used, stress causes cracks to develop. These appear as raised lines on struck coins. Small die cracks add minor interest; large, dramatic cracks can command premiums of $5–$50+.
Die Cuds
A cud forms when a piece of the die breaks away at the rim, leaving a blank, raised area on the coin. Cuds are more dramatic and valuable than cracks. Major cuds covering significant portions of the design can bring $50–$500+. The website cuds-on-coins.com catalogs known examples.
Die Varieties
Every die is unique. Intentional and unintentional differences create collectible varieties:
- Repunched dates (RPD) — Date punched more than once in slightly different positions.
- Repunched mint marks (RPM) — Mint mark punched multiple times. Common on pre-1990 coins.
- Die clashes — Obverse and reverse dies strike each other without a planchet, transferring ghostly design elements.
- Polishing varieties — Die polishing removes minor details, creating varieties like the 1937-D 3-Legged Buffalo.
Variety Attribution Systems
- Cherrypickers' Guide (FS numbers) — The standard reference for US coin varieties.
- VAM (Van Allen-Mallis) — For Morgan and Peace dollar varieties (6,500+ cataloged).
- CONECA — Combined Organizations of Numismatic Error Collectors of America. Maintains variety listings.
Up Next
This guide is for educational purposes. Where official standards, grading services, organization memberships, or legal requirements apply, consult the primary authority named in the references below or the relevant government agency.
Reviewed on March 9, 2026 by the US Coin Shows editorial team. Editorial policy
Frequently Asked Questions
What is a cud on a coin?
A cud forms when a piece of the die breaks away at the rim, leaving a blank, raised area on the coin. Major cuds can bring $50–$500+.
What is a repunched mint mark?
A mint mark punched more than once in slightly different positions, creating doubled or overlapping letters. Common on pre-1990 US coins and collected as die varieties.
Apply what you've learned