The U.S. Mint has released platinum coins for both collectors (proofs) and as a new investment vehicle for those interested in diversifying their commodity investments (bullion).  Though gold and silver have been available from the U.S. Mint as typical stores of wealth for individual investors, it was not until 1997 that public law 99-61 authorized the minting of American Eagle Platinum Bullion Coins and offered another precious metal investors could add to their portfolio. 

American Eagle Platinum Coin Design
John Mercanti engraved the obverse (heads side). The obverse features "Portrait of Liberty", a close-up of the Statue of Liberty.  The obverse for American Eagle Platinum Bullion, Uncirculated, and Proof editions are all the same. 
The reverse (tails side) of the American Eagle Platinum coin varies a bit.  The American Eagle Platinum bullion coin reverse was engraved by Thomas Rogers and has been produced as such since 1997.  However, The proof version varies and has a new engraving every year.  So, what did they put on the uncirculated coin reverse? Please see Editions for more information.  

American Eagle Platinum Coin Editions and Mintage
Though the American Eagle program was launched in 1986, it wasn't until 1997 that a platinum coin was minted.  From 1997 through 2006 only two types were available; the Bullion (for investors) and the Proofs (for collectors).  In 2006, an Uncirculated line was added to bullion and proofs.  Like the American Eagle gold program they are available in four denominations:
American Eagle Platinum One Ounce - Marked $100 face value
American Eagle Platinum One-half Ounce - Marked $50 face value
American Eagle Platinum One-Quarter Ounce - Marked $25 face value
American Eagle Platinum One-Tenth Ounce - Marked $10 face value 

American Eagle Platinum Coin Specifications

American Eagle Platinum One Ounce Coin
-- Content: 0.9995 Fine Platinum
-- Weight: 1.0005 Troy Ounce (31.120 grams)
-- Diameter: 1.287 inches (32.70 mm)
-- Thickness: 0.094 inches (2.39 mm)
-- Edge: Reeded

American Eagle Platinum One-Half Ounce Coin
-- Content: 0.9995 Fine Platinum
-- Weight: 0.5003 Troy Ounce (15.560 grams)
-- Diameter: 1.063 inches (27.0 mm)
-- Thickness: 0.069 inches (1.75 mm)
-- Edge: Reeded

American Eagle Platinum One-Quarter Ounce Coin
-- Content: 0.9995 Fine Platinum
-- Weight: 0.2501 Troy Ounce (7.780 grams)
-- Diameter: 0.866 inches (22.0 mm)
-- Thickness: 0.052 inches (1.32 mm)
-- Edge: Reeded

American Eagle Platinum One-Tenth Ounce Coin
-- Content: 0.1001 Fine Platinum
-- Weight: 0.5003 Troy Ounce (3.112 grams)
-- Diameter: 0.650 inches (16.5 mm)
-- Thickness: 0.037 inches (0.95 mm)
-- Edge: Reeded

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