Well, I tried to find bargains on Asian coins and I think I got burnt on one of these, so I'll post pics to get feedback from some experts to learn and allow others to learn. Mind you, I do some screening with online sellers and use my gut feeling, but there's no way to tell until you see and measure a coin. The Chinese Fat Man strikes me as authentic, since it weighs correctly (26.8 grams) and has the right diameter (39 mm). The seller deals in antiques and seems to be experienced in dealing with coins. He is not a fly-by-night Asian operation. I am fairly confident about that coin. The Japanese yen I believe is fake, because it seems unusually large (40 mm), though it weighs as it should (26.8 grams). My understanding is that these should be more like 38.5 mm in diameter. I believe large fakes were produced in Asia that have actually become collectible themselves, though I don't know if this is one of them. I am also uncertain as to the composition of this coin. Let me know what you think about these coins. I am eager to get feedback from experienced collectors. Fortunately, I did not spend a whole lot on these coins and can easily prove the source of the yen coin due to distinctive features on it.
As an update, the seller of the yen has offered me a refund, and admitted the diameter should be 38.6 mm. I believe the seller played coy and hoped that the coin would not be measured carefully by the buyer. Also, on the eBay front, I reported a coin dealer for selling a grossly underweight silver yen, which on the listing is said to be under 20 grams. The seller refused to remove his listing despite my inquiry, and in fact placed the coin up for sale once the original offer expired.
Grab the refund! Actually a Meiji 27 (1894) yen should be 38.1mm, not 38.6. The changeover occurred in Meiji 20 (1887), the only year in which a genuine coin could have either diameter. 100% certain that yours is a fake. Tell me about the edge on your Fat Man. The edges of genuine Republic Year 3 (1914) 1 yuan coins may be plain, vertically reeded, have a series of incuse circles, or have "T"s alternating top and bottom orientation. Also, are the fields grainy? I can't tell from the pictures.
Well, here are more pics of the Fat Man, including the edges: The surface is flat and smooth, not grainy. This coin looks and feels authentic to me, considering how it is banged up. It seems to have aged naturally. It also has that unique silvery luster on aged coins. But then, I'm just a rookie at this. Regarding the yen, I will be sending it back ASAP.
I am confused though because Numista and other sources say the coin should weigh 26.4 grams, which would mean mine is .4 grams over, while many collectors online in various threads claim that 26.6 or 26.8 grams is what one should expect. Perhaps the Chinese mint had variation in weight? For example: http://en.numista.com/catalogue/pieces3849.html
From the pictures, the chinese coin looks authentic. Sometimes a few points of grams off is okay provided its not too much.
Your weight is pretty much at the far edge of acceptable variation. The early Chinese milled coins were not as precisely weighed as the ones from the Japanese mint at Osaka. The edge looks pretty good, and I son't see any real red flags in your pictures.
Here is mine (not a dollar but 20 cents): and the 'Fatman' was a pretty interesting man called Yuan Shihkai. http://www.cachecoins.org/china01.htm
I verified today with a couple of general coin experts (not specialists in Asian coins) that my Fat Man is predominantly silver, based on the appearance, feel and ring. So I'd say there's a strong chance it is authentic. Notably, we looked through a couple of World Coins books and found that, depending on the year or issue, the Fat Man could range from a standard weight of 26.4 grams all the way up to 26.8 grams (one issue had it at 26.6 grams, and I was assured the book is considered authoritative). So, in addition to the widespread counterfeiting of these coins, it appears as though the goal posts have a small range rather than remain fixed, as with other famous coins, making it harder to determine authentic ones. This supports my previous conclusion derived from online sleuthing that the Fat Man has an acceptable range in weight that is wider than most 20th-century issues, due to inconsistencies in its minting.
