The 1921 silver dollar is a Morgan dollar, which was minted from 1878 to 1921. Morgan dollars are made of 90% silver and 10% copper, and they weigh 26.73 grams. The obverse of a Morgan dollar features a portrait of Lady Liberty, while the reverse features an eagle with outstretched wings.
Morgan dollars were originally minted to help stabilize the economy after the Civil War. However, they were also popular among collectors, and they continued to be minted even after the economy had stabilized. The 1921 silver dollar is one of the last Morgan dollars to be minted, and it is therefore considered to be a valuable collectible.