Do you think you have one? Show us your Nickel and we will tell you if it is a Die Adjustment or not.
Actually can't find the 1970 now, but I also have a 2013 D that has a spot in the field. What would cause a nearly perfect circular field (has a small scratch at one point on the circumference) that has abut the same texture / appearance as a die crack ? It does not appear to be a cleaning spot