That might a Struck Through Grease area? I see the area under the ear and on the neck. There is also an area near the rim on the motto that also looks affected. So the grease might have prevented the strike on the jaw area.
Side note: Look at the edges of the cladding on your coin. Note that one side of the coin has what appears as more of the cupro nickel showing. I figure that must be because of the cutting of the blanks, the side with more silver showing was the direction of the punching out of the coin from the webbing. It pushed the silver color downwards to make it longer from the direction of the punching of the blank.
Side note: Look at the edges of the cladding on your coin. Note that one side of the coin has what appears as more of the cupro nickel showing. I figure that must be because of the cutting of the blanks, the side with more silver showing was the direction of the punching out of the coin from the webbing. It pushed the silver color downwards to make it longer from the direction of the punching of the blank.






















