Unboxing NGC-graded World Coins

@joecoincollect and @TheFinn :

Yes, these coins are brass, but I believe the name "bronze" comes from the market name of this metal (90% Copper - 10% Zinc, which is close to this 88% Copper - 12% Zinc composition), and is called "Commercial Bronze." The Korean numismatic community took that name, cut off the "Commercial" part of the name, since that's so hard to say with it's three(!) syllables, and just called the coining metal "bronze."

The Koreans are accustomed to doing this with foreign loan-words that they incorporate into their own language, especially English words, e.g. "men's skin lotion" becomes the oddly creepy-sounding "men's skin (맨즈스킨)" in the Korean language. There are many other examples of such atrocities committed on English-language words taken into Korean, but I'll spare you.

As for the 10-Won coins, the Korean numismatic community also uses the word "brass" to describe the post-July 16, 1970 strikes of the 1970-dated 10-Won coins, which were struck in a copper-reduced 65% Copper -35% Zinc, due to rises in copper prices at the time. I believe that this is also a shortening of the word, "High Brass" which is another market name describing any brass metal that is at least 33% zinc in composition.

The TPGs even took up this Korean loan-word terminology, with NGC until just a few years ago attributing 10-Won and Five-Won S. Korean coins as "BRONZE" or "BRASS" (for FREE, by the way, not anymore!). Notice that I had to pay SEVENTY-FIVE DOLLARS for each of those metal analyses, that is, IF I wanted my coins to have the variety attribution on the tags! Notice how THAT used to be free. It seems that they've taken a hint from the airline industry and are charging for stuff that used to be free.

Take a look at how this has changed:
#1 and #4 are the old labels, and #3 is what you get nowadays if you don't pay NGC $75 bucks, and #2 is what you get if you do.

 

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@mlov43 Are these korean coins rare or ?

 

Rare? Well...

As far as anybody knows, there is no exact data on the average condition of the existing examples of these coins. Even the official mintage is somewhat of a mystery, since 157 million is listed as the 1970 10-Won coin's production, but this includes both the coins struck on 88%Cu-12%Zn planchets, and the coins struck on the 65%Cu-35%Zn planchets after July 16th that year.

In the numismatic market, the prices for these coins can go as high as this ($625 in current exchange rate for one in MS-63 in South Korea):


And as low(?) as $340 for this one that I bought in an unusual government-issued set on eBay at Christmastime last year, and is the first coin that you see in the video here and NGC graded at MS-64:


So, is the "Bronze" variety of 10-Won coin dated 1970 rare?
The only information that I have is that people have been paying increasingly higher prices for them since about the early 2000s, so it seems that the higher-grade examples are scarce, at best.

I'd LOVE to know just how rare these are.

 

@mlov43 thanks for your answer, wow I'm blown away at the prices especially since its a modern coin! Any idea of the population of the 88% copper one?

 

Nope. The mintage total for 1970 was 157 million. Neither the Bank of Korea nor the South Korean Mint separates the two metal varieties by number of pieces minted, they just list the total altogether.

Perhaps when I get permission, I can ask this question when I hopefully am able to do research at the Bank of Korea or its Mint sometime in the near future...

 

I saw that the metal analysis costs $75. Wow! So, unless you pony-up the extra cash, they don't differentiate. Ridiculous. I could see charging what they charge for variety attribution ($15), but that is just doing a half-assed job.

 

Thanks for your helpful response. Since you have studied these coins extensively and seen many examples, could you figure out which have the lower zinc amount (12) vs the higher amount (i think 35)? In other words, is the metallurgic analysis necessary if you could just eyeball it? Id imagine that looking at enough mint state graded examples might allow you to do this.

 

@joecoincollect I was actually ask this same question, I wonder is it possible to eyeball and figure out which is the 88% one vs the 65% one?

 

oh, i didnt see it. Yeah, it's a good question. I know for indian head cents, the older ones had 10-12 percent of nickel in them and this gave a different look to them.

 

@joecoincollect and @Mkman123

I was pretty sure that both of the 10-Won coins that I had submitted in the OP video were the "bronze" varieties. There is ~generally~ a difference in color tone with mint state examples, but not so much with circulated examples. I had seen some mint state examples that you couldn't really tell due to how toning can change color over time.

The color of the "bronze" varieties have a kind of a golden color, while the "brass" varieties are "yellower" and less golden. Again, toning can change this, while I have seen at least one example of some idiot who had "cherryjuiced" (artificially toned) what was probably a "brass" variety. That coin was in a Details holders because of it.

The reason why you may want to have these coins' authentication verified is that you can get a higher return when you resell these coins, since there will not be any argument between you and the seller over what variety your coin is, since XRF analysis of the surface metal composition doesn't lie.

 

You also mentioned that there is a weight difference between the two varieties, which would be the easiest and least expensive method of variety attribution.

 

good point. Is there a weit difference? By how much? Sorry, just curious.

 

4.22g (bronze) vs. 4.06g (brass)

However, I wouldn't exactly be relying on weight: These coins were made at a time when the South Korean Mint didn't exactly have the best control over measurement tolerances on their coins. But weight could also be used...