2015 United States Mint Proof Set - 14 Pieces! About 1 1/2 ounces of pure silver. The 2015-S United States Mint Silver Proof Set contains 14 coins in stunning proof condition displayed in three protective lenses. Each of these 2015-dated coins bears the “S” mint mark of the United States Mint at San Francisco. The quarters, half dollar and dime are struck in 90% silver, generally referred to as "coin silver."The coins included in this set are:* (5) quarters from the America the Beautiful Quarters Program saluting Homestead National Monument in Nebraska, Kisatchie National Forest in Louisiana, Blue Ridge Parkway in North Carolina, Bombay Hook National Wildlife Reguge in Delaware and Saratoga National Historical Park in New York* (4) Presidential $1 Coins honoring Presidents Harry S. Truman, Dwight D. Eisenhower, John F. Kennedy and Lyndon B. Johnson* (1) Native American $1 Coin with the reverse featuring Mohawk Ironworkers.* (1) Kennedy half-dollar* (1) Roosevelt dime* (1) Jefferson five-cent coin* (1) Lincoln cent