Produced by the United Staes Mint at San Francisco, each proof quarter bears the “S” mint mark of that facility. These quarters are produced from carefully selected planchets, or coin blanks, that have been burnished to a high luster. The polished blanks, which are carefully handled to minimize scratches and abrasions, are sturck on specially adapted coining presses. Each coin is struck at least twice to bring forth the most minute detail with remarkable clarity. Each coin is produced in lustrous 90% silver.
U.S. Proof Coin Sets: 2009 Silver U.S. Territory Quarters
2009 District of Columbia and the U.S. Territories Quarters Silver Proof Set