By "no mark" do you mean "no mintmark"? If so, that would mean your coin was minted in Philadelphia. (The Philadelphia Mint does not place mintmarks on cents.) As usual, a photo would help.
1990 penny no mint mark No mint mark I have a pix on my profile somewhere but it's to small I will try to scan another one
Punctuation is your friend. Are you saying your coin has no mintmark?? If so it is a common, ordinary cent that was produced by the Philadelphis Mint (which does not place mintmarks on cents).
This is true 99.99999% of the time with this coin. Is there something about it that makes you think it is special?
