The newest addition to the buffalo lineup is a one ounce, fifty dollar gold coin, which began in 2006. The minting of the new coin was authorized by the Presidential One Dollar Coin Act of 2005 and are the first pure gold (.9999 fine) coins issued by the United States. The US also mints gold bullion coins with a design by Augustus St. Gaudens, which contains ten percent copper.
In September, 2008, the mint suspended the sale of the coins stating that inventories had been depleted. It is unclear when (if ever) they will return.
The mint originally sold the proof versions of the coins , while uncirculated coins are sold through distributors. Many of the coins are graded and slabbed by the Professional Coin Grading Service (PCGS) and the Numismatic Guarantee Corporation (NGC). Since the coins are made of soft gold, it is expected that they will scratch easily. Coins which have grades of MS69 (indicating no blemishes visible to the naked eye) and MS70 (no blemishes seen even when magnified) sell for premiums. Currently PCGS MS 70 buffaloes are much scarcer than NGC MS70 buffaloes, which indicates an inconsistency in the grading procedures. The PCGS MS70 coins are, therefore, the most valuable. Since an MS69 and an MS70 coin are indistiguishable by the naked eye, Dr. Planchet does not understand the huge premium and demand for the grade MS70.
The coin was based on the original design by James Earle Fraser. the obverse portrait is a composite of three Indian Chiefs while the reverse is an american bison, modeled after one from the New York Zoological Garden.
More information on buffalo gold coins can be found at buffalogold.us