Identifying 40% Silver Kennedy Half Dollars
The most important authentication factor for 40% silver is the date. Only Kennedy half dollars dated 1965 through 1970 contain 40% silver. This is the single most important thing to verify.
Earlier dates (1964) are 90% silver and worth significantly more per coin. Later dates (1971 onward) are copper-nickel clad with no silver content. Mixing these dates would significantly affect your silver holdings' value.
The good news: 40% silver Kennedy half dollars are genuine U.S. Mint products with essentially no counterfeiting concerns. Your main verification task is confirming correct dates, not detecting fakes.
Visual Identification Methods
The edge of a coin reveals its composition. 40% silver Kennedy halves show a silver edge with a thin copper line visible in the middle (from the clad construction).
In contrast, 1964 Kennedy halves (90% silver) show a solid silver edge with no copper line. Post-1970 clad coins show a distinctive solid copper stripe along the edge.
The Kennedy half dollar grading images and specifications provide detailed visuals across all years, useful for comparing edge characteristics and identifying dates.
Weight Verification
40% silver Kennedy halves weigh 11.50 grams. A precision scale can verify this. Post-1970 clad halves weigh the same, but pre-1964 90% silver halves weigh 12.50 grams.
For bulk verification of a bag, spot-checking a random sample of coins for correct dates and weights provides reasonable assurance without examining every coin.
Buying from Reputable Sources
The simplest authentication approach is purchasing from reputable dealers who guarantee their products. Established precious metals dealers stake their reputation on providing accurately described inventory.
When buying from unknown sources (estate sales, private parties, online marketplaces), more careful examination is warranted. Verify dates carefully and consider having large purchases examined by a knowledgeable numismatist.
For significant purchases, the peace of mind from buying through established channels typically outweighs any small price advantage from alternative sources.