2001-S United States Mint 90% Silver Proof 10 Coin Set In OGP w/ COA COMPLETE! DO NOT MISS THIS DEAL!! LISTED IN US MINT CONDITION! As with most all coins, eventually some will show some natural toning. Side note, the natural toning on the “kittyhawk” quarter is quite interesting! ALL ITEMS LISTED TO THE BEST OF OUR KNOWLEDGE. (1) 2001-S United States Mint 90% Silver Proof 10 Coin Set In OGP w/ COA COMPLETE! (Camera props not included).