As Mr. Jerzy Chałupski noted in his *Specialized Catalog of Polish Coins*, minting errors from the Second Polish Republic are rare. Errors account for less than one per mille of the mintage of these coins, and are often one-of-a-kind pieces. In their beautiful form, they are a real treat, gracing many a sophisticated collection of coins from this period.
This coin is a very rare and striking mint error.
It is a so-called “indent error,” resulting from two coins striking the dies simultaneously. Upon striking, the upper disc is pressed into the lower one, leaving a distinct indentation on it after it falls away. Here, the overlap is clearly visible, covering nearly three-quarters of the coin.
