Your coin is in a Blister/Flat Pack
Had a couple of sets in the past with same markings only on TONED copper coins.
my theory a hair or piece of lint was on the die or planchet/flan before striking or after striking.
The lint or hair was greasy / oily so stops that part of coin from toning
So line becomes visible when coin tones
Had a couple of sets in the past with same markings only on TONED copper coins.
my theory a hair or piece of lint was on the die or planchet/flan before striking or after striking.
The lint or hair was greasy / oily so stops that part of coin from toning
So line becomes visible when coin tones





















