Katherine P. writes: I am wondering how many ridges the U.S. Quarter dollar, and the U.S. dime have?
Reeded edge coins have their origins in the days when coins were minted in precious metals. It was a way of preventing people from rubbing off or clipping some of the metal from the coin. A coin with a damaged edge was obvious and more likely to be rejected because of the missing metal. Reeding is imparted by the collar that holds the coin blank in place when it is struck by the coin dies. The number varies from time to time but I think there are about 160 reeds on either coin.
There are some coins that have reeding varieties. One example is the “infrequent reeded” 1921 Morgan Dollar, One variety of this coin with far less reeding than other dollars of this date. ‘Not the first coin on a variety collectors list but a good example nevertheless.
It is possible to count the reeds. Make a mark with a pen or pencil on the edge of the coin and count until you come back to the mark.