Circulating coins used to be made out of valuable metals like silver and gold, in addition to copper. As these metals got more and more expensive, the U.S. Mint started replacing them with cheaper and longer-lasting metals. The last coin to include silver was the 1970 half dollar.
Fun Fact! Your pocket change used to go farther. Before 1933, the Mint made gold $2.50, $5, $10, and even $20 coins for people to spend.
Some coins are sandwiches...
Today's coins are made from metals such as nickel, copper, and zinc. Instead of using one metal to make a coin, multiple kinds of metal are pressed together into layers. This is called a "clad" coin. The layers of a clad coin are like a sandwich.
On the outside of a quarter --the bread-- is a nickel-copper mixture that is silver in color. The inside filling is copper. The layers of metal help the coin last a long time. Look at the edge of a quarter and you can see the copper color peaking out! The dime is the same.
Coins are made of different metals and sizes...
Notice that the color of a penny is different than the dime and quarter. The penny has more copper. The copper metal sandwiches an inner layer made mostly of zinc.
The nickel is different from the other coins because it's not a clad coin. It is nickel and copper metals mixed together instead of placed in layers.
Each coin is also a different size. The sizes and metals of the coins do not relate to the coins' value or worth.