What it is
Roosevelt dime proofs struck at San Francisco since 1968 should carry an S. A few proof dies were sent out without it, creating some of the rarest modern US coins: the 1968, 1970, 1975 and 1983 No S proofs. Only two 1975 No S proof dimes are known.
How to identify it
- The coin must be a proof, with mirror fields and frosted devices, usually in original Mint packaging.
- No S above the date.
- Check the field for any sign the mint mark was removed.
A 5x to 10x loupe and good, angled light make the details much easier to see. For anything that looks genuine, a digital scale and a certified comparison coin help.
What gets mistaken for it
Removing an S from a proof leaves marks in the mirror field that are visible under magnification. These are high-value coins: certification is a must.
Why proof dimes need an S
Proof coins were made at Philadelphia until 1964. After a break from 1965 to 1967, when Special Mint Sets replaced proofs, proof production moved to San Francisco in 1968 and every proof coin from then on carried an S. The S was punched into each proof die by hand until 1985. If a die was missed, the coins it struck had no S.
Proof dies are used for far fewer strikes than circulation dies, so a missed proof die produced a small number of coins. That is why the No S proof dimes are so rare.
The four No S years
The 1968 No S proof dime was the first. The 1970 and 1983 No S dimes are the ones collectors are most likely to encounter, since examples turned up in proof sets of those years. The 1975 No S is a famous rarity with only two known examples.
Each year's coins came from a single die or a small number of dies, so each is a separate rarity and collectors treat them as four different coins.
How to check a proof set
Use a 5x or 10x loupe and an overhead light. Look above the date on the dime, where the S should be. Check whether the field there is mirror-like and unbroken. Then check the other coins in the set: a No S set will have S mint marks on the other denominations, which confirms it is a San Francisco set.
Do not remove the coin from its holder to check it. Original packaging helps prove the coin was not tampered with. Handling a proof leaves fingerprints and hairlines on the mirror fields.
Faint S and filled S coins
Some proof dimes have a weak or filled S that looks almost invisible, caused by grease or debris in the die. These are not No S dimes. Under a 10x loupe a faint outline of the S is usually visible. Grading services attribute only coins with a completely missing S as No S.
If you see even a trace of the S, the coin is a filled S, not the rarity.
Altered coins
Removing an S from a proof dime damages the mirror field, but on a cleaned or polished coin this damage can be hidden. Experts compare the surface above the date with the rest of the field, check for die markers and compare with known genuine examples. This is why certification matters for these coins.
Grades and finishes
Proof dimes are graded from PR60 to PR70. Many also receive Cameo or Deep Cameo designations, showing contrast between frosted devices and mirror fields. A No S dime in a high grade with Deep Cameo contrast is the most desirable. Hairlines from cleaning and spots from poor storage are the most common problems.
Authentication
PCGS and NGC certify No S proof dimes and note the year and designation on the label. These are high value coins, so buy only certified examples and confirm the certification number online.
Related No S proofs
If you think you have found one, keep the set exactly as it is, photograph the dime in its holder and send the whole set to a major grading service. Insure the package for its full value and keep a record of where the set came from, since a known history adds confidence to any rare proof.
Other No S proofs
Other No S proofs include the 1971 nickel and the 1990 cent. The 1982 No P dime is the business strike equivalent: a Philadelphia dime with a missing P. Collectors interested in No S proofs often look at all of these together.
Frequently asked questions
How do I know if I have a No S Proof Roosevelt Dimes?
The coin must be a proof, with mirror fields and frosted devices, usually in original Mint packaging. No S above the date. If your coin passes these checks, have it authenticated by PCGS or NGC before buying or selling.
Is the No S Proof Roosevelt Dimes valuable?
Genuine examples sell for a premium over regular coins of the same date. The amount depends on how strong the variety is, the coin's condition and whether it is certified. Compare recent sold auction results for certified coins in the same grade.
What is a missing mint mark?
A missing mint mark error occurs when the mint mark was left off a die that should have had one, or was filled with grease during striking. Read more about missing mint marks.
Which No S proof dime is the rarest?
The 1975 No S proof dime is the rarest, with only two known. The 1968, 1970 and 1983 No S dimes are rare but more available.
How do I check my proof set for a No S dime?
Look above the date on the dime with a loupe. If no S is there and the field is unbroken mirror, have the coin authenticated.