The 2019 Silver Proof Set features coins with mixed metal compositions. The dime, quarters, and half dollar are composed of 99.9% fine silver this was the first year the U. Mint transitioned these specific proof coins to. 999 silver instead of the traditional 90% alloy. The full 10-coin set consists of the following compositions:Dime, Quarters, and Half-Dollar: 99.9% silver and 0.1% copper. Native American Dollar: 88% copper, 6% zinc, 3% manganese, and 3% nickel. Jefferson Nickel: 75% copper and 25% nickel. Lincoln Penny: Copper-plated zinc (99.2% zinc, 0.8% copper). Five America the Beautiful Quarters® Program Coins honoring Lowell National Historical Park (Massachusetts), American Memorial Park (Commonwealth of the Northern Mariana Islands), War in the Pacific National Historical Park (Guam), San Antonio Missions National Historical Park (Texas), and Frank Church River of No Return Wilderness (Idaho). The obverse (heads) of all coins bears John Flanagan’s 1932 portrait of George Washington.