Here's an interesting NGC slab that I saw. The label says "Brass Planchet". These 10 Won S. Korean coins were being struck in 88%copper, 12%zinc at the time, and this coining metal is called "bronze" by collectors and TPGs. How did a lower-copper-ratio "brass" planchet make it into the hopper? The only "brass" (60%/40%) coining metal was for the much smaller 1 Won coin (in 1966, 67). Or do the graders even know that this is "brass" for sure? Anybody else have a "wrong planchet" error?
I don't and I never even thought about getting one until I saw this thread. Now you have competition. j/k
For those who don't understand the implications of this - this coin, if it was indeed struck on such planchet could be quite interesting. mlov - I know you are well aware of the history but for the sake of everyone, I might as well write a brief history. Please feel free to correct me as I am working off my memory. In 1966, a new set of coins were released for South Korea. Coins of 1 won were struck of brass like quality because of the low face value (60% Cu, 40% Zn). However in 1968, these were struck in aluminum due to the gradual increase of copper price. 10 won coins were struck in higher quality copper content (88% Cu, 12% Zn). This and 5 won coins were also affected by copper prices and around the middle of 1970, these coins were struck in lower quality copper alloy. Therefore, this coin, if it was really struck in one of the lower copper content alloy would be quite interesting, if not bizarre. Personall I don't believe this is the case and it could be a case of misattributing.
Just a quick question (I should be working ): Wouldn't bronze basically be Cu-Sn alloys while brass is Cu-Zn?
Yes, bronze is tin and copper and brass is copper and zinc. But with an issue like this it is more a matter of the color of the coin than anything else. Darker colored coins are usually "called" bronze and lighter "colored" coins are called brass. It doesn't matter that they are both really brass, with one having a percentage of zinc than the other. The higher the percentage of zinc the lighter the color. So technically, the coin is not struck on a different metal, the metal is the same - brass. It is just struck on a planchet with a higher zinc content in the alloy.
Its true more zinc will obviously create a more yellow (i.e., brassy) looking coin. I go into this in my new book coming out in a year or so on contempoary counterfeits made in a brass alloy and verified with XRF analysis. Still a 12% Zn level may create the same coloration as 20% Zn piece given different environmental environments (i.e., exposures). IMO ... this is not an error ... XRF analysis may with further investigation show a differential of say 12% ZN on most and 20% Zn on a select few ... not a big deal IMO ... and not a large Zn differential either ... John Lorenzo Numismatist United States
I have Estonian 10 senti, which is struck on Finnish 10 penniä planchet. The coins were struck in Estonia, but the planchets for the coins were bought from Finland (Outokumpu Porikopper OY). So, this coin is 1.8 grams instead of 1.87 and white or gray instead of yellow (cupronickel instead of aluminium-bronze). It's interesting, that NGC didn't even notice, that the color of the coin is different
The history is correct, and I agree with everything you said. Interesting if it IS a "brass" planchet, but hard to believe. Too bad the TPGs are not approachable about justifying their judgements. I understand the reasons why they are not, but it places the rest of us in an odd situation where we are not sure that the TPGs get things like this right... And who are we? Just the customers, that's all.
So, you think an XRF analysis would be able to determine 88%cu,12%zn versus 60%cu,40%zn, or not? Not a large differential? Then how do we correctly attribute/discriminate these two varieties from each other? Like you said, color tone is not always the way (I think I've seen some of these 10 Won coins that a TPG said were "Brass varieties" when I had a hunch that they may have been "Bronze Varieties"). How about specific gravity? Would the fineness of the measurements require a laboratory environment?
Yes, you are technically correct, of course. However, we're talking about "collector terminology," not actual metallurgy. I think it was the casual collectors/dealers who called these different 10 Won and 5 Won varieties "bronze" and "brass", and the TPGs picked up on it. Now even they put this terminology on their little paper tags inside their graded holders, as you see above.
Maybe this is and actual 1970 Brass? Can the date be read on these coins? I want to share this website with you - https://en.wikipedia.org/wiki/South_Korean_won *EDIT - Forget what I said I just answered my own question! This is your coin and it is 1966.
Oh and by the way, did you cover up the NGC number? You can still scan the barcode and get the info. I wonder why people sometimes do this? Is it a secret coin?
It depends on the coin and what they (the TPGs) know about it. There are actual off metal strikes, have been for centuries. They are usually test strikes or one kind or another, and sometimes they are even plain old fashioned mistakes. And of course there are always the out and out counterfeits thrown into the mix. About the only way to tell one from the other is if you happen to have the requisite knowledge. This coin for example, it is an off metal strike. The Hieronymus 1782 ducat is a gold coin of course and this one obviously isn't. When I bought it there were no recorded sales of this coin ever in auction catalogs or books on the subject, so I bought it. A year or so later I managed to find another example - And not too long after that a friend, aware of the examples I had, found yet another and he bought that one. So in just a few years a previously unknown coin had 3 examples known. Later on, others even showed up. The coins were all struck in white metal (base metal) exact composition unknown. But to this day I know of no book that explains them or states exactly what they are. But I am reasonably sure that were someone to do the needed research in the archives they could find records of it. And that usually seems to be the case, that no one has ever taken the time or spent the effort to do the research. But in the book that I helped write on Netherlands ducats, the research was done and off metal strikes were documented.
So the off-metal strikes on these ducats were documented by the Dutch Mint? I don't know, but I suspect that the Korean Mint didn't really document much. If it WAS an accidentally-struck brass planchet, my only guess is that the planchet came from some leftover(?) planchets from the previous year's (1965) test strikes (see http://www.dokdo-research.com/koreanpatterncoins.html), where they experimented with differing Cu/Zn ratios. I really like countries where they consider the printed word an "important thing" and not just a scrap of paper to be discarded after a certain amount of time. To make sure this isn't the case, I have to try to see if there actually is anything to research by going to Korea (armed with a fake impressive title and letter from the ANA -a little tip from Don Pfeiffer, a Korean medal expert) to see if I can open some doors and figure this out. Koreans aren't much impressed by "interested hobbyists," and they pretty much ignore them. What was your experience in accessing the Dutch archives?
Pretty much all mints document everything. For example, when Stahl wrote Zecca, he found the original mint documents for the Venetian mint dating back to the 13th century. And yeah they still exist. The only issue is finding the documents in the archives. But it does require going there and doing it. This is known as primary research. And yeah you have go through all of the red tape to do that before you even start researching. Now sometimes you can find things in secondary research, this is when you find the results of previous primary research done by somebody else. But that's when you begin to into problems because you don't always know for sure if what you find comes from primary research, or secondary, or 3rd or 4th or whatever. And when one author starts copying previous authors, that's when the mistakes get repeated. This why a great many books have mistakes in them, because they were copied from previous authors and merely repeated by the current author. So when you're doing research, you have to research your research. And I wasn't the one who accessed the Dutch archives, that was done by Darek Jasek, ( he lives in Europe), the guy I helped to write the book. Suffice it to say that a lot of mistakes in the few previous works were corrected.
Hm, I thought I posted a reply but it disappeared on me. Here is an example that I took a while to remember. I thought I didn't have an example in my collection. Coins from this era were struck in German; in Munich if I recall correctly. This is a Latvia 1992 20 sentimu struck on a nickel-brass planchet This is a plated steel version, which is similar to a German 10 pfennig coin. While this was somewhat common a few years ago, I have not been keeping track how scarce it is these days.
Munich is right; the Bank of Latvia orders coins from many places. This is the list of mints for the pre-euro coins. And yes, the 20 santīmu coin had a similar look, and precisely the same diameter (21.5 mm), as the 10 pfennig coin. As for the value, my 2014 catalog says €25 in vz (roughly EF) for the planchet error ... Christian
