3 grosze coin [solved]

Hello! I have bought a 1622 3 grosze coin. But I cant figure out which type it is. The condition is not too good. The side of where the king is, is barely visible. But I can see that the king has three lines of collar rings (don't know what they are called) but all of the ones on the internet have only two lines. Does anybody know something about this coin? Also sorry for the bad pictures, couldnt get a good closeup photo. Thanks for helping!

Welcome to numista, 

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We need better images, and the measurements and the supposed alloy of your item, if you don't help us, we can't help you…..

Here's  better pictures with measurements if that helps. Well the coin is silver. It looks almost identical to the one in numista catalogue, and thats why I am asking if the variation of the count of the lines are common, or if this is something more special. Thanks for the tips! Attached the link of the numista coin. N#22123

That's not measurements worth of anything, but better than nothing. The weight and thickness are parts of the measurements, right. The diameter might be 20 mm, but your ruler is not really showing that clearly. 

I just did a fast cropping of your images:

The coin doesn't look like silver at all.

I suppose the lines you mention are below the collar of the king? Your coin is really too used to give a valid opinion on that, sorry. That's my opinion only, others might have younger and clearer eyes than my 78 year old ones.

The coin weighs 1.20 grams.  It may not look like silver because of my yellow light. But it is silver. Also I think the coin has been dug out with a metal detector and thats why there are signs of oxidation, and also thats why there is a small piece missing and the coin being just a bit lighter than it should be.  

I think you've found the correct coin.  That obverse is pretty worn, so it's entirely possible that the collar matches.  There are no notes about variants in that regard.  It isn't called out, but if we extrapolate from the details for the 1618, I would say you have the K.22.1.b (since yours has the full “POLONI” on the reverse.)

Thanks. Well yes, hammered coins are basically all unique as the way of making them wasnt very precise. So this “difference” could just be from striking the coin. But interesting anyways! Thanks for helping. 

It is K.22.1.a.

On K.22.1.b the reverse legend has REGNI.

Oh, yes. Do you know the reasons why the letters change ? 

Die variation.  There is no change in the meaning.

Descriptions of these variants have now been added to the catalog listing.