And as far as the OP's coin... I have no idea what happened. Maybe if we had a hint at what we're supposed to see, and some nice clear pics, a non-alien answer might be forthcoming.
the first picture i posted is clear enough to show what i am talking bout , if you look at the picture its easy to see that the face is incomplete , part of it is missing, so no a alien answer really isnt necessary here
It may be clear enough for you because you still have the benefit of viewing the coin in hand. Unfortunately for us, the photo is out of focus and too dark. The alien comment was not directed toward you or your coin. It was directed toward rickmp, so you can relax a bit. Chris PS. My first impression of the coin with the photo shown is that it has been mutilated.
To the OP- as far as I can tell from the pictures, the coin looks like it has an indent on it. If there was a gouge or other impoerfection on the die, it would have made a raised mark on the coin. This makes me think it was damaged after leaving the mint. Also, you should always hold a coin on the edge between your fingers, as oils on your hand can damage coins.
This is a nice struck thru error coin . If it had been done outside the mint the reverse side would be also damaged. Something has been in between the planchet and the die when the coin was struck and got pushed into the coin. after being struck the foreign object has fell out of the coin leaving the depression.