Counterfeit Detection: 1925 Stone Mountain Half Dollar

By Numismatic Guaranty Corporation

The 1925 Stone Mountain half dollar has one of the largest mintages of any classic commemorative, with more than 1.3 million pieces struck. (The 1893 World’s Columbian Exposition half dollar is the only issue in this series with a higher mintage.) Thanks to their great abundance, Stone Mountain halves often are less expensive than other coins in the commemorative series. However, just because they are affordable does not mean they aren’t counterfeited.

A 1925 Stone Mountain half dollar recently caught the eye of Numismatic Guaranty Corporation (NGC) graders. While the coin initially appeared to be a genuine Mint State specimen, it is, in fact, a well-known counterfeit that first appeared in the early 1980s.

The counterfeit's luster (bottom) is out of character, and the horse’s hindquarters are not as distinct as those on a genuine half dollar. Click images to enlarge.

The level of detail is quite good, although the horse’s hindquarters fade into the field more than they do on authentic examples. This piece is 93-percent silver rather than the standard 90 percent. It also is slightly lighter at 12.46g versus the normal 12.5g. Nevertheless, the fake’s composition and weight are close enough to U.S. Mint tolerances to fool many collectors and dealers.

Notable are the counterfeit’s surfaces, which have a very odd luster that is quite unlike that of genuine half dollars. At the bottom of the obverse, below the horse, several spikes can be seen at the rim. These are toolmarks accidentally left by the forger and will appear on all fakes struck from this die.

LEFT: Toolmarks are evident along the bottom rim of the obverse. RIGHT: Diagnostic depressions on the reverse were transferred from the host coin. Click images to enlarge.

The most damning piece of evidence is the depressions below the eagle on the reverse. At first these appear to be the result of circulation, but a closer look reveals that the luster inside them is identical to that of the coin’s surfaces. (Normal “hits” would show fresh metal, which would be brighter than the surface.) These depressions are the result of damage to the original coin from which the forger created his dies. Because these imperfections were transferred to the reverse die, they will show up on every coin struck from it.

NGC President and Finalizer Rick Montgomery spotted this fake and was very intrigued by its appearance. “I instantly recognized this counterfeit as one identified in the early 1980s. However, it seems to have been updated over the past few decades, as the finish is more lustrous. These used to be much more common, and it is possible that counterfeiters have made more recently.”

If you are concerned about your authentication and grading skills, it is best to purchase a coin encapsulated by a third-party grading service such as NGC.

Reproduced with permission from the April 2019 edition of The Numismatist, official publication of the American Numismatic Association

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