Ron Guth:
The 1842 Quarter is a great, low-mintage date that is also the second rarest (in terms of overall population) of all the Quarters from the 1840s (only the 1840 With Drapery is rarer). In Mint State, the 1842 Quarter is slightly more plentiful than the super-rare dates such as the 1843-O and the 1847-O, but the problem with the 1842 is that most of the Mint State population is at the low end of the scale. The collector is most likely to encounter an MS62 in the marketplace, while MS63 and MS64 examples show up far less frequently. Gems may not exist at all - they certainly have not shown up in the last several decades.