Hello guys and gals, I was going through some rolls of Lincoln cents and discovered this 1994 D . Something is obviously up with the mint mark. It looks like the first mint mark that has its own tent . I think I see a little doubling on the date but probably not. I did a little research to see if there was a known RPM or error of this date and didn't really find much. But I know you guys will tell it like it is. You guys have busted my bubble more than once so I'm already prepared to hear damaged, or perhaps a simple nothing. Speaking of nothing, here goes nothing....... Let the comments begin!
Plating blisters develop in the coin in the immediate aftermath of the strike, as gas expands between the core and poorly bonded plating. Among domestic coins, plating blisters are the exclusive province of copper-plated zinc cents. Blisters are generally small and sub-circular, with a smooth surface and soft outline. They can occur anywhere on the field and design. The design continues uninterrupted as it crosses a blister. (Info from coinworld.com) No added value (NAV). You might want to keep for educational purposes or as a curiosity.
It’s a plating blister. Close to popping if it stays in circulation. Very common and only worth one cent.
Sorry. I guess I should have gone more into the difference between defect and error. In this context, a defect is an irregularity (problem) with the coin which had nothing to do with the minting process, aside from poor quality raw material, in this case. An error is something wrong with a coin that resulted from human error, before or during the minting process. A defect just happens, usually with no human input. An error is a mistake. Post-mint damage- anything that happened to the coin after it left the mint- can also fall under the “defect” category, whether or not humans had a hand in it. Since this coin was struck properly at the mint (no mistakes), it can’t be considered an error. Confusingly, some quality control issues (like major laminations, for example), do get classified as errors, if only because the mistake was, “hey, they should have seen this, and never used such a poor quality planchet to strike a coin”. Severe quality control issues being the mistake (error) in this example. But this coin probably looked normal when it left the mint. The plating blister just happened, later. So not an error. There was no mistake in how it was made, despite it being a poor quality product. Hope this makes sense?
A break in the plating by the mintmark has allowed water and oxygen to get at the zinc and zinc rot has set in below the plating. As the zinc reacts and forms zinc oxide it swells up below the plating and forms that "tent" that you describe.
