Mexico is the only country that uses silver coins for its currency, as of 2015. The silver used in Mexican currency is in minute amounts, with other metals such as nickel and copper more commonly found.
The use of silver as currency dates back to the earliest kept records. Silver coins were first minted and used for currency in the Mediterranean region around 550 B.C. and were eventually adopted by the Roman Empire as its standard coinage and spread with the spread of trade afterwards.
Most nations were on a silver standard up until the late 1800s, and silver made up the bulk of currency in circulation. Today, however, most countries only use silver when creating special proof or commemorative coins or bullion. For instance, the Royal Canadian Mint issues a $5 Silver Maple Leaf coin that is 99.99 percent fine. The U.S. Mint's Silver Eagle bullion coin, which is a 1-ounce coin that has a face value of $1, is another example of special coins made of silver in modern-day society. Previously minted coins, including the 1878 through 1921 U.S. Morgan silver dollar, are highly prized for their collectible value. Finally, another example is Australia's Kookaburra, a $5 silver coin made using an ounce of 99.9 percent fine silver bullion.