I have a penny that is blank on one side and some kind of clear coat on the other. What is it and what is it valued?
I am afraid what you have there is a damaged cent. Somebody ground down the obverse and glued it to something. Probably wanted the cent to be perfectly flat when they adhered it to whatever display they had. The blob you see on the ground down obverse is glue residue.
No need for 2 threads.. It's an altered cent. Not even worth 1 Cent anymore. Not a mint error of any kind.
Welcome to CT Karl. I see you posted twice; once in Coin Chat, and then again here in What's It Worth. Most members here read new posts, regardless of the forum category so one post is all you need. As you can see, your question was answered, so hope you are satisfied. Also, I post this for new members: For the best results, you should post "in focus," FULL IMAGE photos (after you upload your photo, two buttons appear: Thumbnail and Full Image, click Full Image and your photo appears full size on your post and are easily enlarged by clicking on it). Photograph coins on neutral backgrounds like black, grey, or white. Crop out superfluous background so just the coin shows (you can use https://www.remove.bg for free), and post photos with correct orientation so members don't have to turn their computer in some awkward fashion to view it properly. While it isn’t always necessary, it is nice to show both the obverse and reverse, even if your question is just about one side. Members can often give more valuable information having both sides to evaluate. Add close ups of areas you have questions about and make your questions as definitive as possible so we know what you are asking for. And try to have the best lighting possible to show the most favorable photo of the coin. Hope this helps in the future. Good luck.