Missing Mint Mark

What it is

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.

What causes it

Human error in die preparation, or a filled die.

How to identify it

• The area where the mint mark should be is smooth and undisturbed.
• Check whether the mint actually used a mark that year before assuming an error.
• Proof coins without an S are especially valuable.

How to tell it from damage

Mint marks can be scraped or filed off. Removal leaves scratches visible under magnification.

How a mint mark could be left off a die

Until 1985 for proofs and 1990 for circulating coins, mint marks were added to each working die by hand after it was hubbed. A die that skipped this step, or a die prepared for Philadelphia that was sent to a branch mint, struck coins without the branch's letter. Since the mint mark became part of the master die, true omissions have become much rarer, though not impossible.

The other route to a missing mint mark is a filled die. Grease and debris can pack the small mint mark recess so tightly that the letter does not strike up. Filled-die examples are usually treated as struck-through errors rather than die varieties, unless a die was so worn and filled that every coin from it lacked the mark.

When a missing mint mark is not an error

Many coins never carried a mint mark. Philadelphia coins had none for most of US history, apart from the wartime nickels of 1942 to 1945 and most denominations from 1979 and 1980 onward. Philadelphia cents still have no mint mark except those dated 2017. No US coins carried mint marks from 1965 through 1967, when the Mint removed them during a coin shortage.

Some cents struck at West Point and San Francisco in the 1970s and 1980s also carried no mint mark, so they look identical to Philadelphia coins. The first question for any coin without a mint mark is whether coins of that date and mint should have one at all.

Famous missing mint mark coins

The 1922 plain Lincoln cent is the classic. Only Denver struck cents in 1922, so every 1922 cent should carry a D. Some Denver dies became so worn, filled or heavily polished that the D disappeared, producing cents with a weak or missing mint mark. The strongest variety, with no trace of the D and a sharp reverse, is the most sought after.

The 1982 no-P Roosevelt dime came from a Philadelphia die that was not given its P, only two years after Philadelphia began marking its dimes. Proof coins, which should always carry an S in these years, have produced several rarities: Roosevelt dimes of 1968, 1970, 1975 and 1983 without an S, the 1971 no-S Jefferson nickel and the 1990 no-S Lincoln cent. The 1975 no-S dime is among the rarest of all modern proof errors.

Checking the mint mark area step by step

Find the correct mint mark location for your coin, because it has moved over time. On Lincoln cents it sits below the date. Roosevelt dimes carried it on the reverse until 1964 and above the date on the obverse from 1968. Jefferson nickels carried it on the reverse before 1965, apart from the large wartime marks above Monticello. From 1968 it moved to the obverse near the date.

Examine that spot with a 10x loupe. On a genuine missing mint mark coin, the field there is smooth and continuous with the surrounding field, with the same luster, or the same mirror finish on a proof. A faint outline or bump suggests a weak or filled mark, which is a different and usually lesser coin. A business strike with no mint mark is almost always just a Philadelphia coin, so be sure the date and design rule that out before going further.

How removed mint marks give themselves away

Removing a mint mark is the main alteration. A file, scraper or abrasive takes off the letter, but it also cuts into the field around it. Under magnification the area shows fine parallel scratches, a slight depression, a change in luster and sometimes a raised edge where metal was pushed aside. On a proof, removing the S destroys the mirror surface in that spot, which is very hard to hide.

The reason is physical. A mint mark stands above the field, so it cannot be removed without disturbing the field around its base. A genuine missing mark leaves the field untouched because the letter was never in the die.

How missing mint mark coins are attributed

Grading services attribute the listed missing mint mark varieties and the major proof rarities are bought almost entirely as certified coins. For the 1922 cent, attribution separates the strong reverse no-D die from weaker dies and from cents that show a faint D.

Frequently asked questions