The 2012 S United States Mint 14 Coin Silver Proof Set includes a collection of uncirculated silver coins from the San Francisco Mint, each struck with a high level of proof finish. This set comes with a box and Certificate of Authenticity from the U. Mint, making it a valuable addition to any coin enthusiast’s collection. Each coin in the set is composed of 90% silver and is guaranteed to be of the highest quality.