If you have a 1990 no mint mark penny, it could be a quite rare and valuable proof cent, or it could be a circulating cent from the Philadelphia Mint.
We will explain how to distinguish one from another below.
Origins of the 1990 No S Proof Penny
The 1990 no S mint mark penny was produced as a result of changes from the previous decade and a mislabeled mint state die.
Until 1985, U.S. Mint staff punched mint marks into active coin dies. In 1985, mint marks were placed directly on the hub, which saved a good deal of production time for employees.
But it also helped to create an error coin.
In 1990, a mint state die was sent to the San Francisco Mint labeled as a proof die. Mint staff had become accustomed to mint marks that were already on the die over the past five years, no one noticed the missing S.
Since the San Francisco Mint does not produce circulating pennies, there would have been no reason to differentiate between the circulating and proof dies at the time.
In July of 1990, Jim Gullen identified the error.
Later, the Mint stated that there were a number of 1990 Proof Lincoln cents struck in San Francisco without mint marks. It was also stated that 145 examples of the proof cent error were destroyed.
Proof coins are specifically made for collectors. They are struck multiple times in the minting process to have intricate details and the highest quality.
Value of a 1990 No S Mint Mark Proof Cent
Depending on its condition, the value for this proof cent is in the thousands of dollars, potentially as valuable as $6,000 if it is in PR-69 or better condition.
And this error coin is unique out of more than a century’s worth of Lincoln proof pennies. The 1990 no-S proof cent is the only Lincoln cent proof since 1909 without a mint mark.
The rarity of the 1990 “No S” penny is the cornerstone of its collectability. Aside from the 145 cents that the Mint destroyed, there are fewer than 200 known surviving cents.
As a result, collectors have tirelessly sought out these coins, creating a robust market for them.
How Can I Tell the 1990-P Circulating Penny From the 1990 No-S Proof Cent?
This test will be simple and requires no tools, but you may want to use a magnifying glass or loupe.
Using your eyes, examine your coin. Shine a light on it. Would you describe the fields, of areas around the design, as having a mirror like shine?
Do Abraham Lincoln and other design elements look frosted?
Are the details sharp throughout the coin?
If you have answered yes to these questions, you might have a valuable coin. Your best course of action is to send it to the Professional Coin Grading Services or Numismatic Guarantee Company for grading.
Having your 1990 no mint mark cent graded will not only help determine if it is the elusive no S proof cent, but it can also help you sell it. As there are a scant number of these known to exist, having yours authenticated will make yours stand out.
The 1990 no S mint mark proof cent is an anomaly in numismatics with significance beyond its value and scarcity. It reminds collectors that even in an age of advanced technologies and intensive quality control measures, errors can occur.
And the smallest error can turn something pedestrian, like a penny, into an object of extraordinary value and prestige. The story that surrounds it makes it a highly coveted item for numismatists and casual collectors alike.
