R-, 20 groszy 2005, mint proof, damaged, 180-degree flip

A very rare coin, struck with a die rotated 180 degrees. The eagle on the obverse is upside down relative to the images on the reverse—a so-called "reversed die." A beautiful piece, with a mint luster and details untouched by circulation. Collecting full "ODWROTKI" in uncirculated condition is one of the most challenging and fascinating areas of numismatic collecting, and a larger collection makes an incredible impression. In coin collections from the last century, machine-struck in vast quantities, it is not the number of coins that determines the quality of the collection, but the number of gems it contains. There is no higher class of gems than low-mintage TRIALS, and even rarer than these are the interesting minting errors (misalignments, reverse-sided coins) that occur by chance.