NNP

Variety.  A numismatic item differing from all other items of the same type, even if the difference is minute. Such a difference is the result of a change in the die (if struck),

or in the mold (if cast), as re-engraving a die crates a new variety. Numismatists study these variations. The greatest number of varieties occur in changing the date, somewhat

less in the lettering or detail. A major variety can be the addition or deletion of a single word of a single character, or change in a design element; a minor variety would be, for example, a broken die with part of a letter filled.  See die variety.

excerpted with permission from

An Encyclopedia of Coin and Medal Technology

For Artists, Makers, Collectors and Curators

COMPILED AND WRITTEN BY D. WAYNE JOHNSON

Roger W. Burdette, Editor