The 1990 Lincoln Penny: a common find, yet some are worth more than face value.
Key factors: mint mark, condition, and rarity determine a penny's value.
Pennies with no mint mark were produced in Philadelphia, often in large quantities.
Look for the 'S' mint mark, indicating a proof coin from the San Francisco Mint.
1990 proof pennies can be valuable, especially in pristine, uncirculated condition.
Error coins, like the 'No S' proof penny, are highly sought after by collectors.
Professional grading can authenticate and assess a penny's condition and value.
Check auction sites and coin catalogs for recent sales to estimate your penny's worth.
Always consult with a numismatic expert before selling to ensure a fair price.