The most valuable silver coins sell for millions of dollars ... Half-dollar coins were still made with 40% silver from 1965 to 1970, but after 1970 no more circulating U.S. coins were made with silver ...
Rare and unique coins can be more expensive ... joined together in the 1970s and established CoinGrading standards. These numismatists now assign grades at key places on the seventy-point scale, using ...