Collectible coins, particularly those from the United States, often include various types such as commemorative coins, proof sets, and special mint releases. The 2017 Proof Set, produced by the San Francisco Mint, features high-quality coins struck with a shiny, mirror-like finish, enhancing their aesthetic appeal. This set typically includes coins from various denominations, with the 25-cent coin (quarter) being a notable inclusion, showcasing unique designs representative of American heritage or symbols. Proof sets are highly sought after by collectors for their limited mintage and superior craftsmanship.