Hey, I have been looking at a lot of errors here, and the thought came into my mind, is it possible that two planchets can be stacked on top of eachother before the striking and then struck giving one the image of the obverse and one of the reverse with the center being blank? I am no error collector or expert, but the thought struck my mind. ~Cannyn
I'm sure they are out there but once the two coins leave the coining chamber the odds get slim that they will stay together. In other words, unless both coins end up in the same bag or roll and someone searches that bag or roll and finds both of them, the two coins will probably be found by different people and not paired up. Mike Diamond is the resident error expert here but I believe the two coins in this example would both be a brockage.
Basically you are asking can two planchets enter the coining chamber at the same time and be struck so that you have two one sided coins. Yes it can happen. The struck side of each coin will have an extremely strong strike and I would expect the rim on the anvil side coin to be fully struck up and possibly squared off. The hammer side coin will quite possibly show a partial collar strike all the way around because with two planchets in the coining chamber the upper one will probably not be fully restrained by the collar. The rim may not be fully formed because the metal can move outward rather than filling the rim. The blank sides of the two coins will NOT be flat and smooth and where the blank sides meet the edge they will be uneven with high and low areas as you go around the coin. This is because the metal as it expands and reaches the rim will try to move toward the hammer die for the anvil coin and toward the anvil die for the hammer coin. Since it will not reach the collar at the same time all the way around in some areas the metal will move down and in others it will move up.
A brockage is a coin struck by another coin, or part of another coin, which was previously struck. It would not be uniface.
