Well-struck versions of the 1917 D Buffalo Nickel are rare, but rarer still are those ... so that many wore down to the point the date was no longer legible. Less than 10 million out of 63 million ...

This Buffalo nickel was originally struck with a date of 1917, then struck again with a date of 1918, meaning the 7 is still visible beneath. As Luxe Digital pointed out, one finer example of this ...