The introduction of the 2000 “golden” dollar depicting Sacagawea resulted in another new alloy. U.S. Mint officials selected a composition that has two outer layers composed of manganese-bronze (77 percent copper, 12 percent zinc, 7 manganese and 4 percent nickel) bonded to an inner core of pure copper. Overall, the total composition is 88.5 percent copper, 6 percent zinc, 3.5 percent manganese and 2 percent nickel. The same alloy is used in the Presidential dollars and Native American dollars.
The American Eagle 1-ounce .999 fine silver bullion coin was joined in 2010 by the America the Beautiful 5-ounce .9999 fine silver bullion coin. The America the Beautiful 5-ounce coin is 3 inches in diameter and is both the heaviest and largest-diameter U.S. coin ever issued.