The following Q&A is excerpted from Clifford Mishler’s Coins: Questions & Answers:
Q: Is there more than one variety of the Peace dollar?
A: There are two major varieties of this coin. The 1921 dollars were struck with concave fields and high relief on the Liberty portrait and the at-rest eagle. The 1922 to 1935 dollars were struck with flat fields and shallower relief on the features. While some 35,000 silver dollars of the high relief variety were minted in early 1922, most if not all of them were subsequently officially melted; 1922 Proofs do exist in both the high and low relief varieties, with the low relief being of greater rarity. The high relief coins have eight rays below the eagle’s tail and four below the “N” of “ONE.” The low relief coins have six rays below the tail (seven have been reported on some of the later dates) and three below the “N.”