2 Grosze Y# 9a, Schön# 6a, N# 4113, made in bronze, is listed only from 1925 to 1939 but I have a coin from 1923 that is made by bronze not brass, like 2 Grosze1923, please see pictures:
I can suppose that the emission was similar to the 5 grosze, where there is brass 5 Groszy for1923 and bronze 5 Groszy from 1923 to 1939.
Im sure you have a much better understanding of what your coin is made of (in hand as compared to images), but your coin looks like it has either been in a fire or buried in the ground for a long time, certainly environmental damage, and so under that tarnish, damage may certainly be a brass coin and not a bronze coin? Your images are hardly conclusive.
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Correct, there is no referee at the moment for Polish coins. So the task must fall to one of the Master referees. I volunteered to be the referee for polish coins but was to to get lost in a round about way.
Also no one has a Bronze 2 Grosze from 1923 that is obviously bronze and not brass, the coin here is almost certainly brass with environmental damage, how that has changed the colour I do not know, but it is highly unlikely the only know example (pictured here) happens to be extremely damaged and it is far more likely the coin is brass referred to in the catalogue segment (imaged) as „yellow bronze“ i.e. Brass.
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From the above catalog extract, both 2 grosze and 5 groszy have been produced using brass (so called Yellow bronze, only 1923) and bronze (from 1923 to 1939). The 5 groszy is already reported on Numista catalog.
Regarding my coin, to prove it's made by bronze I've slightly filed the edge and (from picture is not very well visible) it's pink material, then normal bronze with higher percentage of copper.
From the above catalog extract, both 2 grosze and 5 groszy have been produced using brass (so called Yellow bronze, only 1923) and bronze (from 1923 to 1939). The 5 groszy is already reported on Numista catalog.
Regarding my coin, to prove it's made by bronze I've slightly filed the edge and (from picture is not very well visible) it's pink material, then normal bronze with higher percentage of copper.
Yes I understand what you believe, (you are essentially saying you have the only 2 grosze made of bronze dated 1923 in the world), I am just putting up a counter argument because it is highly unlikely that a single coin from 1923 made of bronze (your coin which has bad environmental damaged) exists. The 2 Grosze in bronze is from 1925 onwards, 1923 is brass (the catalogue extract shown is incorrect for the 2 Groszy years, a mistake on Y 9a - it should be 1925-1939) there are no examples of a bronze 2 grosze from 1923, only brass. Your example has been damaged, probably in a fire and then possibly buried in the ground which may explain the pinkish colour of the metal underneath the darkened patina. Please remember that Brass is made of Copper and zinc, and bronze is copper and tin, the pinkish material you see is as you stated correctly copper, which is present in both Brass and Bronze.
An X-Ray fluorescence test is the only way to prove decisively either way, and my money would be that it shows as Brass, or it will show as copper because the zinc, has through the environmental damage (heating from a fire or some reaction from being buried) been separated from the copper and produced the dark patina on the surface, leaving the red pinkish material of copper visible underneath.
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Or more likely, exposure to cleaning fluids (vinegar, household cleaner, bleach, etc. - see my 10 pfennig from an earlier post). All of these will cause the same separation of the copper.
If somebody can perform an X-Ray fluorescence test, I would be happy to send Him the coin…
Anyway, why there should be an error on the catalog when the 5 groszy 1923 bronze is really existing?
An XRF is something you need to sort out yourself to prove your own theory, against all the evidence that says there is no such coin.
The 1923 5 groszy as far as I remember was a proof run in bronze, the main production was in brass - after the proof run, the Bronze 5 groszy started minting in 1925, just like the 2 Grosze. There was also a probe coin of 2 Grosze (bronze) in 1923 with a different design, so it is unlikely they would have proofed the design of the brass 2 grosze in bronze if they were thinking of changing the design.
But let me say this as a final word, you as a Member and Coin Referee have the right to make an amendment to the 2 Grosze coin page and add the year line 1923 to the Bronze Version of the coin - but you have absolutely no evidence this coin exists (apart from your environmentally damaged coin, which you believe is made of Bronze) and all other sources (apart from one catalogue, which you have not provided information for, and thus is likely a mistake) say there was no such coin, which prevents you from providing sources to justify the coin page change. Likewise there is no other example of a 1923 2 Grosze in Bronze of this design anywhere in the world!
„If your reply or post in the Forum stinks of AI, I will call you out! Knowledge comes from experience, the I in AI stands for incompetence.“
