Error coin? 1989 D Lincoln Cent

[Shadmin]

I have a coin here which I found in my pocket change a while back. The lettering on the obverse side is missing except for the "rust" from "In God We Trust" and the "LIBERTY" which is weak. The 1989 appears to be doubled and the mintmark is weak and tilted a bit. I have looked at this coin under high magnification since I thought the coin had been abraded or something at first. This was not the case since the finish and patina is intact. It appears the problem occurred during the minting process. Not sure what was struck through though to cause this error? I have included several pictures of the coin. Tell me what you think? Thanks!

[diamond]

The coin was struck through some kind of lubricant, probably oil, given its smooth consistency. The doubling is the result of die deterioration. Both errors are pretty common among copper-plated zinc cents.

[wavysteps]

Hi Shadmin and welcome to the forum.

Your coin was more than likely struck thru grease during the minting process. The weakness, or in some cases, missing letters, numerals is caused by dirt and grease clogging the recesses of the die and not allowing metal flow into those areas.

The doubling on the date appears to be from a worn die and is described as die deterioration doubling. Over a period of time, metal flow over the surface of the die, will actually erode that surface causing it to grove. The resulting affect is what you see, a slight doubling.

BJ Neff