Discussion & Detection
While most past counterfeit low-denomination coins targeted coins with numismatic value, modern counterfeit US 90% "junk silver" now exists in nearly every type, date, and mint mark ever produced, including the most common of dates which typically trade only for the bullion value.
Here we compare a counterfeit 1964 Washington quarter to an about-uncirculated genuine quarter and a circulated genuine quarter. The artificial wear on the counterfeit quarter helps to hide any minor imperfections in the design. The strike quality and post-mint wear/damage varies widely among genuine circulated 90% and counterfeit 90% coins, making it difficult to spot these fakes strictly visually. This particular counterfeit quarter was slightly thicker than the genuine quarters, but otherwise very closely matched the genuine quarters.
While there are a few smartphone apps that check the "ring" or "ping" frequency of gold and silver coins, they do not (yet) have settings for 90% silver coins. The counterfeit quarter does ping at a lower frequency than the genuine quarter, but with the genuine coin being a 90% silver alloy rather than pure silver, and with both coins being much smaller than a one ounce coin, the difference in sound between them is less noticeable. Without using a meter or an app to quantify the frequency, the "ring test" leaves room for subjectivity and error.
The Precious Metal Verifier, using the optional Small Wand on the "Silver 90% Coin 1960" setting, correctly identified this counterfeit quarter with a "right arrow" reading. The Precious Metal Verifier PRO, using the small bridge sensor on the "Silver 90% Coin 1945-" setting, also correctly identified the counterfeit quarter with a "right arrow" reading. Testing 90% silver coins with a PMV can be tricky, particularly with older coins where there is more variation in the genuine 90% silver alloy, but is probably still the best non-destructive testing method currently available for testing 90% coins.