amazing. I have never seen one before. Is that due to a weakness in the planchet that it breaks upon being struck?
The best I can do for a blow hole error is that is a defect in the planchet. They form ragged holes. They develop in the coin metal strip as it’s rolled out. The stresses tear apart in areas that are stiff and brittle.
That’s a great example of a blow hole error. Nice it still has some mint redness and that’s it’s from 1961.
Not so sure it is the end of a strip. Could have been an impurity patch away from the end that fractured during rolling or striking
True. @expat I just remembered this from error-ref website http://www.error-ref.com/ragged-perforations/