Duplicate
Duplicate. A collector's term for a second specimen of the same variety already in his collection. Duplicates generally become unwanted and are candidates for disposal. For example, when a collector finds a specimen in better condition for sale than one already in his collection he will often obtain the better piece and sell the duplicate.
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