2008 W American Gold Buffalo. Black Diamond 4 Coin Proof Set. The item "2008 W American Gold Buffalo Black Diamond 4 Coin Proof Set PCGS PR70DCAM" is in sale since Tuesday, April 9, 2019. This item is in the category "Coins & Paper Money\Coins\ US\Commemorative\Modern Gold (1984-Now)".The seller is "savoncoin" and is located in Rancho Santa Margarita, California. This item can be shipped to United States.