The 1990 US Mint Prestige Proof Set includes coins made of silver, minted in Philadelphia. This set comes with original government packaging and a Certificate of Authenticity from the United States Mint. The coins in this set are described as uncirculated and struck in proof condition, making them highly collectible for coin enthusiasts interested in US coins from the 1990s. This set is a valuable addition to any coin collection, especially for those who appreciate the craftsmanship and history of American coinage.