Here is a South Korean 100 Won coin. It's "graded" at MS66. If these images suffice, would the surfaces of this coin set off any counterfeit flags? The "pebbliness" of the surfaces, even over the flat areas and the perimeter design on the denomination/date side of the coin, make me think it's fake. The high-ish price that the seller is asking is also a concern. http://www.ebay.com/itm/331940556075?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT
NGC Certification number checks out good 50,000,000 of these coins were minted in 1974 What makes it so special? I don't see why anyone would make a fake 100 Won coin. The price is ridiculous though.. but the item location is in South Korea and people tend to overprice things on Ebay when they are in Asian countries.
By implication, I'm also wondering if this is a fake slab. I'm not suggesting that NGC graded an obvious counterfeit. I should have made that clear. The coin is one of the key dates, if not THE key date of the 100 Won series.
I know very little about these, but I don't see anything in those pictures that makes it look fake (the slab looks good, too). The grainy surfaces you see could be from either of two effects - without bigger pictures, I'm not sure which: 1. It could be an artifact of the lighting/photography/compression technique used. I've seen a similar look with some low-quality photo editing tools. 2. More likely, it is from a later die state. When the die is worn, it sometimes develops grainy surfaces like this. It is fairly common, especially if they were stretching die life to get the most out of them. You can see a similar effect on this US quarter. I'm nearly positive this is what you are seeing. I don't find the look attractive, and would probably reduce the value for it (given that it is a mint-made effect, it doesn't really hurt the grade):
I don't understand why you consider 1974 THE key date of this series. Other years had mintage numbers way less than in 1974.. 1981 had only 100,000 Here are the numbers -
Here is a coin that has been altered. I'm not very familiar with laser etched surfaces and what the telltale signs are but this one appears to be media blasted under magnification. How ever it was done, it was done to deceive.
Do you have the ability to take any better pictures of this coin? I really don't see what you are describing in these pictures.
Notice the grainy appearance covers all the devices and the rim. Even obvious scratches and dings all have the same surface. If the coin has a ding or an abrasion it should alter the appearance of the surface of that spot.
It's key due to condition rarity: These seem to have been heavily circulated. Hard to find in MS65 or 66. I've never seen these sell for cheap, at least ones sold in/from Korea.
Thank you so much! And thanks for the practical example with the Alabama Quarter! I can see that now. I'm wondering now just how this happens... Does material from the surface of the die just come off? I'd like to know what this is called, in numismatic terminology. I've got a lot to learn about coins... I'd like to start with counterfeit detection for the coins I collect.
It's called die deterioration. It is caused by friction between the coin and die when a coin is struck.