Curious to what is causing this? Help apprciated. (Just to the right of Jefferson head. Its raised like a blister bubble) Probably the 5th one I have seen.
Are they all the same date-mm coins, with the same mark on them? A raised mark usually means the die sustained damage from a hit or was scraped in some manner.
They may be more appealing to someone if there are several together. They are a minor/common error, even with several they hold little value. IMO.