Here is a set of the only gold "circulation" coins of the Second Republic period.
Coins in original box from the communist era, box in export version with inscription in English (POLISH GOLD COINS).
The 10 and 20 zlotys with the image of King Boleslaw the Brave are a design by Zofia Trzcinska-Kaminska, selected in a 1925 competition. The first gold coins were minted in 1926, albeit with a date commemorating the 900th anniversary of Chrobry's coronation. They were minted in accordance with the first monetary reform of the Second Republic, but due to the value of gold being higher than the denomination of the coins, they were not put into circulation.