Do you have a 1975 No S Proof dime?
Recently the news was ablaze with a recent discovery of the 1975 No S mintmark proof dime. Missing the expected S mint mark is not something new or specific for 1975. No S Proof coins have been found in 1968, 1970, 1971, 1983, and 1990. What sets the 1975 No S apart from the other years is that there are only 2 known. That’s it 2. The other dates mentioned above have from a few dozen to several hundred known specimens.
To dive deeper into why these coins are rare is to understand something about coins minted in those years. First off, we must understand the difference between Business Stike and Proof Strike coins. Finding a business strike 1975 Dime without an S, is no big deal. They made 585,673,900 of them. That’s 585+ MILLION of them. You could not get further away from the definition of rarity than this coin. Since the news came out of the 1975 No S, we have received many calls from people claiming to have “found” the No S Dime. But if you do not understand the difference between proof and business strikes, you could be chasing rainbows.
Proof coins are made specifically for collecting. They are actually made differently than normal Business strike coins, and they are sold in sets from the US Mint every year. Without getting too technical, suffice it to say that each is a different “Method of Manufacture” and are made for 2 very different markets. A robust economy uses a lot of dimes, those business strikes are usually made in the millions from each of the major mints. But Proofs are different because they are made to collect, they are made in relatively smaller quantities than the business strikes. Think in terms of 3 Million instead of 585 Million. Still not rare by any measure but certainly a lot less.
In 1968, the US Mint began making proof sets mainly out of the San Francisco Mint. At the time, the demand for business coinage was well satisfied by the Philadelphia (No Mint Mark or P) and Denver (D mint Mark), so the San Francisco Mint started producing Proof Sets. The main Mint in Philadelphia was in charge of creating the master hubs used to make the dies that were used to strike the coins. Because the Mint was unsure which mint would need more or less dies, it would produce them without a mintmark. The mint mark was then added by the appropriate branch mint as they made the dies ready for production.
In the case of the proof dies the mint mark was after the dies was polished to make proof finishes. In each case of the No S coins, it appears that production coins were made BEFORE the S was added. This was usually caught in the quality control aspect of the mint, but sometimes, a few dozen to a few hundred coins were made into sets before anyone noticed. No one knew there were ANY 1975 Proof dimes without an S Mint mark until very recently, and to date, only 2 have been found. So, the question is, did the mint correct the problem after only two made it out the door, or are there more out there? For now, it is just the two and that is why the last one that came up for auction sold for over a half-a-million dollars. You might want to check your Proof sets, but please do not think all 1975 Dimes without an S are worth the big bucks. It's just the ones in Proof Sets….