Paul, George, John & Ringo, To form the loop, there is a tiny column of metal in the middle of the recess in the die. The recess allows the metal to be raised, forming the number (or letter). After striking many, many planchets, this column of die metal can break away allowing the planchet metal to flow into the void. Chris
I understand the concept on the metal flowing in the middle I have quite a few mint marks that are filled very similar I was wondering if these are worth holding on to?
They don't often command a premium, but large ones can be cool. Personally, I hold onto any big ol' die chip I find, Keep up the hunt!