There are two varieties of 1846 half eagle known: the common Large Date and the scarce Small Date. The latter is generally seen in EF and AU grades and it is quite scarce in Uncirculated with probably no more than ten to fifteen currently known. This bright, frosty example exhibits light green-gold color and it is sharply impressed. As on all known examples, there is a mint-made raised mark coming from the corner of Liberty's eye; the fields surrounding the portrait have some mint-made roughness and I have seen this on a few 1846 Small Date half eagles as well. If half eagles of this era become more avidly collected (which I can almost assure you they will be...) I believe that this variety will sell for a significant premium given its widely-known scarcity.
Before the U.S. Mint began producing Proof gold coins in any sort of quantity in 1858, a limited number of proofs were struck in certain years. In 1846, it is belived that around four or five gold proof sets were made and today there are four 1846 quarter eagles known including two that are impounded in museums (Smithsonian and ANS). The other known example is the Trompeter/Eliasberg coin that appears to be graded PR65 by PCGS; it last sold in the 2/91 Superior sale for $52,800. The current coin, from the famous Pittman collection, has a pedigree going back well over a century and it is sourced from an original 1846 proof set that has been broken up. It has the look of a Gem with superb rich amber color over very reflective surfaces that are nearly free of hairlines. An old scratch on the obverse between stars nine and ten removes this from a higher grade and serves as immediate identification. With the exception of the 1841, Proof quarter eagles from the 1840's and early 1850's are virtually unknown and tend to be come available at major auctions. This is a remarkable opportunity for the collector or investor to own a truly monumental piece of American numismatics and it is a remarkable combination of rarity, beauty and provenance.
Ex Heritage 1/11: 5335 ($106,375), earlier part of an 1846 Proof set in the Pittman sale (lot 1712) that brought $522,500; obtained by Pittman from Numismatic Gallery in 1949 and before this part of an original 1846 gold proof set that was in Ed Frossard's November 1892 sale.
Large Date variety. The Large Date is, by far, the scarcer of the two varieties of half eagle produced at the Philadelphia mint in 1846. In Uncircuated, this variety is actually quite rare and I can't recall personally having seen more than a handful in MS60 or better until a small group of MS64's was found in the S.S. New York treasure a few years back. This bright yellow-gold example has a very frosty obverse and a slightly PL reverse with very good detail. There are a number of small, shallow marks in the fields that in keeping with the grade assigned by NGC.
The pre- Civil War Liberty Head eagles from the Philadelphia mint are led by the 1844 and the 1858. The next scarcest issue is the 1846 which is a date that is not as well known as the these two. It is likely that not more than 100 are known and this date is usually seen very well worn with VF and EF coins being typical. The present example shows nice deep natural green-gold color with some fiery orange and reddish undertones. As always, the surfaces are abraded; this is an issue that seems to have been well-circulated and roughly handled. There are no overtly detracting marks and the eye appeal is far above-average for the date. There have been just eight AU55's sold at auction since 2000 and my best guess is that this represents just three or four distinct pieces. The 1846 eagle is just about unavailable finer than this.