1998 United States Mint Silver Proof Set, 5 Coins Inside!. United States Proof Sets 1998 5 coins. All coins included in the set were struck at the San Francisco Mint. Each set contains a 90% silver Half Dollar, a 90% Silver Quarter, a 90% Silver Dime, a Jefferson Nickle and a Lincoln penny. Harder Set. The packaging for the 1992 Silver Proof Set was themed in black, but otherwise similar to the packaging for the regular set. The coins were placed in individual spaces in a black cardboard. This was sealed within a plastic lens with the word “Silver” imprinted. The outer box was black and had silver printing “United States Mint Silver Proof Set 199_”.