Silver was a staple of currency throughout the 18th and 19th Centuries and remained so through World War II. Silver as "circulating currency" (legal tender) has now largely disappeared, but as of 2010, non-circulating bullion coins for investors and commemorative coins continue to be issued by mints around the world.
The threepence, sixpence, shilling, half-crown, florin, double florin and crown were all solid silver. In 1920, the silver content was debased from 925 parts per thousand to 500 (known as .500 fine,) and the use of silver largely ceased in 1947.
Silver coins include the quarter, half dollar and dollar (until 1934.) The last series of silver circulating coins was issued in 1964, although the half dollar continued at .400 fine until 1970. The U.S. Mint continues to be a prolific issuer of non-circulating bullion coins and commemorative coins such as the 1976 bicentennial half dollar.
The last genuine solid silver circulating coin in Europe was the Austrian 10 schilling, which ceased production in 1973. But France produced a rare and collectable 50 franc coin from 1974 to 1980 and a 100 franc coin from 1982 until the changeover to the Euro in 2002.
Identifying Silver Coins
Look for a date on the coin. If it dates from before World War II and is convincingly silvery in colour, then the chances of it being solid silver are very good. Weigh it in the palm of your hand, then do the same with a modern coin of a similar size for comparison. Silver is somewhat heavier than the nickel alloys that replaced it. Lastly, consult a guide such as the "Standard Catalog of World Coins." A guide identifies the weight and silver content of each coin and its value depending on its condition.