Like most my post I am not expecting anything huge here but curious about this 1987D penny that is a beautiful penny in person for being so old. Looks like it has been painted over it is so shiny. Looking at it under the microscope you can see a bunch of bubbles or specks. Read something about coins doing this but eventually rotting through this one doesn't look like it is rotting anytime soon and hasn't yet. Any information would be amazing. Thanks fellas!
The bubbles are a plating issue where the copper plating is separating. the secondary "rim" under your letters is referred to as a ridge ring and is a result of the die deteriorating from use. You may hear the term die deterioration doubling or die wear the more you collect.