This term refers to coinage produced by the United States Mint, specifically the half-dollar denomination, that contains a 40% silver composition. These coins were primarily minted between 1965 and 1970. An illustration would be the Kennedy half-dollar produced during those years, which, unlike its predecessor (90% silver), incorporated a significantly reduced silver content.
The significance of these pieces stems from their intrinsic metal value, derived from the silver they contain. This feature often makes them attractive to both collectors and investors seeking to hold precious metals. From a historical perspective, the change in silver composition marked a shift in U.S. coinage due to rising silver prices and the need to reduce the metal content in circulating currency.