Oh, it's the golden dollar coin, featuring this woman, that was released into circulation on January 27, 2000
^ Jump up to:... [DOC] [TLE] The United States Mint  About The Mint [PAR] The Golden Dollar coin, as required by the United States $1 Coin Act of 1997 ... 
Like any brass, its color will eventually become darker, giving your coins an 
antique finish.