The 1855 San Francisco Die Trials, also known as Pattern coins, were experimental pieces struck to test new designs and technologies for U.S. coinage. Among these, the DT 50 coins are particularly notable for their rarity and significance in numismatic history. These coins were produced in limited quantities and often feature unique design elements that distinguish them from regular issue coins. Collectors value these pieces for their historical context and the insight they provide into the evolution of U.S. coin design.

Item Denomination Series Year Mint
1855 DT$50 Kellogg & Co. Copper Die Trial BN DT$50 Patterns & Die Trials 1855 San Francisco