This was partly to discourage the hoarding of coins during this time of transition, but the D (Denver) and S (San Francisco) mintmarks eventually were used again in 1968. Coins dated 1965, 19 were intentionally produced without a mintmark. In the mid-1960s, the United States was in the midst of a nationwide coin shortage due to a major shift from striking 90% silver coins to those of a less-valuable “clad” composition. Why There Are No Mint Marks on Coins Dated 1965, 1966, and 1967? No S Proof coins are known from 1968 (Roosevelt Dime), 1970 (Roosevelt Dime), 1971 (Jefferson Nickel), 1975 (Roosevelt Dime), 1983 (Roosevelt Dime), and 1990 (Lincoln Cent). A few sets from selected years were accidentally released to the public without the intended S mintmark, however, and are known today as “No S Proofs.” Starting in 1968, the proof coins in these sets were supposed to be minted with an “S” mintmark for San Francisco, the US Mint facility that produces these pieces. Such coins were never released into circulation and typically cannot be found in change as a result. They were housed in hard plastic cases, often with a decorative outer box, and had brightly mirrored surfaces. Proof coins, or special strikes intended for collectors rather than circulation, have been issued in 5-coin proof sets each year for decades.
Specifically, the No S Proof coins that were mistakenly released by the San Francisco Mint. PREVIEW – Check the schedule to find the next rare coin auction. However, a coin with no mintmark can be special when this mintmark was left off by accident rather than on purpose. This is normal and rarely adds value given the large mintages at this important coin-minting facility. Millions and millions of coins have been struck over the years at the Philadelphia Mint with no mintmarks. One of the most common questions that we are asked is about coins without mintmarks or that seem to be missing a mintmark. What are Coins with No Mint Marks, and Are They Valuable?