On the right is a trime, on the left is, I don't know what. I am convinced (although my mind could be changed) it is not a button. Depends on which way I turn the coin, I see many things; things that it certainly is not. Any thoughts?
Known coin measures 9.5 MM on the screen whereas the unknown object measures just over 10MM.
Actual Trime measures 14MM. Based on that proportion, the unknown object has a diameter of nearly 15 mm.
Don.......
Can't see any features in your photos. Maybe some better closeup of the item. You might also try to take a pencil rubbing off it. That might bring out some details.