The 1921-S Walking Liberty Half Dollar has a relatively low mintage of 548,000; which is a moot point as this issue has the lowest survival estimate and is viewed as the official key date of the series. Interestingly enough up to VF, it is not quite scarce at which point takes a massive jump into XF which is scarce. Then it becomes truly rare in the AU to low-end Mint State range. MS63 through MS66 are all extreme rarities at varying levels. Strikes of this date are somewhat average with decent luster and mostly white pieces as toning, is scarce.