The 1852-O Dime is a semi-scarce date that is difficult to locate in Mint State. The mintage for this date is 430,000 coins, which is relatively high for the series, but few of the best coins were preserved by collectors. The best examples seen by PCGS include several MS64's. However, the finest example may be the gem from the Louis Eliasberg collection.
Jerry Fortin has identified only two different die pairs that were used to strike 1852-O Dimes. They both share the same obverse, so one must rely on the reverses to tell them apart. The most obvious difference is in the size and shape of the mintmark.