It's weird, and I think I need to change my setup because when I photograph coins head on, they look a little dull and lifeless. At an angle, the luster lights up. This is the coin at a slight angle which shows full luster.
I think GrapeCollects is correct about the collar being slightly off . BTW I know you took that slant photo to show some luster on the coin but please reframe from doing it again . Your straight head on photos look 100 times better .