How to Identify the Grosz Koronny

Read the Two Faces

Start by matching the designs. A Grosz Koronny of this type pairs a Polish royal crown set above a coat of arms or shield on one face with the Polish Eagle (Orzeł), wings spread, on the other. If one side does not show either the crown-over-shield motif or the spread-winged Eagle, you are likely looking at a different denomination or a coin of another country.

Find the Legend and Date

Look around the rim for a Latin inscription. On a genuine piece it names the king and his titles in abbreviated Latin and includes a grosz denomination spelling such as GROSSVS. The date, here 1527, appears in the legend as well. A readable royal legend and a clear date are strong confirmation of the type and are also what drives collector interest.

Check Size, Weight, and Metal

This is a small silver coin, roughly 20 mm across and only a couple of grams, so it should feel thin and light, not thick or heavy. It should be non-magnetic and show the gray tone or patina of old silver. A coin of this design that is oversized, thick, brassy, or attracted to a magnet is a warning sign.

Expect a Hammered Look

Because it was struck by hand, a real grosz of this era is often slightly off-round, unevenly centered, and stronger in detail on one side than the other. Do not treat modest irregularity as a fault of authenticity; instead be suspicious of pieces that look too perfectly round and uniform, which can indicate a cast copy or a modern replica.

Rule Out Look-Alikes and Fakes

Poland and Lithuania struck many small silver coins with eagles, crowns, and shields under Sigismund I and later rulers, so read the legend and denomination rather than relying on the Eagle alone; Lithuanian issues, half-groschen, and later-dated groszy share the family look. Watch for altered dates, tooled detail, cast seams, wrong weight, and cleaning. For any better example, compare against trusted reference images of dated Sigismund I groszy and, where value warrants, seek third-party authentication.