PCGS No: None

Mintage:
Circulation strikes:  0
Proofs: 1

Designer: Christian Gobrecht

Diameter: 38.1 millimeters

Metal Content:
Silver - 90%
Copper - 10%

Weight: 26.73 grams

Edge: Reeded

Mintmark: "O" (for New Orleans, Louisiana) below the eagle on the reverse

Images courtesy of Ira & Larry Goldberg Coins & Collectibles, Inc.

Known examples (1):
ANACS Proof-62 (illustrated above). 

Notes:
The 1851-O Silver Dollar is one of the most mysterious and little known American coins.  The date does not appear in the GUIDEBOOK or in Walter Breen's "Encyclopedia", nor does it show up in Mint Reports for the period.  Nevertheless, this is an authentic coin that was struck at the U.S. Mint, albeit under suspicious circumstances.

Breen believed that this coin was struck surreptitiously at the Philadelphia Mint sometime in the 1860's to 1870's by employees utilizing an 1851 Obverse and an "O"-mintmarked Reverse.  He believed that whoever made this piece attempted to remove the mintmark upon discovering that they had inadvertently created a previously unknown rarity.

On October 18, 2002, I (Ron Guth) examined the coin in the offices of Ira & Larry Goldberg Coins & Collectibles, Inc.  I viewed the coin with the following possibilities in mind:

Possibility #1: that this was indeed a muling of an 1851 Obverse with an "O"-mintmarked Reverse.  Finding: the mintmark is clearly visible but completely flat.  While there are some very fine, almost microscopic scratches in the area of the mintmark, I believe that this was an attempt to efface the already flattened mintmark, not to remove a raised mintmark.  

Possibility #2: that a Silver Dollar previously struck at the New Orleans Mint was mistakenly overstruck in the process of creating an 1851 Restrike Silver Dollar.  Since no Silver Dollars were struck at the New Orleans Mint in 1851, the only possibilities for the host coin were the 1846-O, 1850-O, 1859-O, and 1860-O dates.