Featured Authenticating Chinese Part II: Ji Mo Knife

Discussion in 'Ancient Coins' started by TypeCoin971793, Oct 14, 2019.

  1. TypeCoin971793

    TypeCoin971793 Just a random guy on the internet

    I recently bought a rare and potentially extremely-valuable knife coin where the dealer was uncertain about its authenticity. It was marketed as a contemporary counterfeit because the consignor (a friend) had XRF data showing the coin to be majority lead. I liked contemporary counterfeits, the coin looked ancient enough, and the price was right, so I bought it. I know the collection, so I knew this coin had a pre-1990 provenance.

    About a year and a half ago, I posted a thread where I worked through a logical analysis of exceedingly rare coins in an effort to authenticate them.

    https://www.cointalk.com/threads/authenticating-exceedingly-rare-chinese-coins.321153/

    I think it would be interesting, as well as helpful to those interested in ancient Chinese coins, to repeat the same exercise for this coin.

    My Process

    I always start from “what do I see on the coin” and compare the observations to to what I would expect from a counterfeit or genuine coin. To fit snugly in one of the two categories, any additional observations must be plausibly explained. Once this process is completed, I have a pretty solid conclusion about the authenticity of the coin. The three main aspects analyzed on this coin are the style, the patina, and the metal.

    The Style

    Qi knives were cast to an amazingly high quality, especially the 4, 5, 6+ character knives. This knife is a five-character JiMo knife with the inscription 即墨之法化(“Jo Mo Zhi Fa Hua”).

    5E9169CB-B9B9-4278-8F0C-A98CCFD13AE8.jpeg

    All Qi knives have very sharp character strokes and lines. The rims on the reverse can often have a flattened “worn” appearance. The font of the characters must match those of known genuine specimens (not necessarily an exact match because the moulds were hand-made). There should not be random gaps in the strokes. The circle around the hole at the end of the handle must have rounded edges (no flat edges like that on modern coins. The right, obverse rim must terminate at the joint of the blade and handle. The width of the handle must be relatively wide compared to normal Qi knives (the knives whose first character is “Qi”).

    On the subject coin, all of the character strokes and lines of the design are very sharp. The patina buildup on the characters makes them seem thicker, but there are areas where the patina is chipped away where the sharp strokes can be seen. The fonts match known genuine coins. The shape of the coin is consistent with genuine coins, though the handle is on the thinner side of acceptability. The edges of the hole are rounded. Therefore, the style is consistent with genuine coins. This is very important as it is one of the hardest things to get right.

    There are gaps in some of the lines on the handle, but they appear to be due to legitimate corrosion. When such coins are used to create fake moulds, the inscriptions would have random gaps without any apparent corrosion, such as the fake spade below.

    BF97A2D0-B1BC-4F29-9897-D1B4C620CAB2.jpeg

    Here are two genuine Qi knives. Note how sharp all of the design elements are.

    E88792CB-1410-4C38-A443-436A6EA5B9FC.jpeg 212FA5DE-9D74-4ECF-A51F-1AF8D4769F9E.jpeg

    Here is a counterfeit 6-character knife from the 1980s, which was considered state-of-the-art in the day. Note how the lines in the handle on the obverse are thick and are somewhat softly blended with the surface. The reverse is extremely soft and completely unlike genuine coins.

    E8242CEF-9A15-4D2F-B406-3EA72A3864AA.jpeg

    Here is a lot of six genuine knives from a recent auction (so not mine) which excellently portray the correct style of these knives.

    0DD7BAED-B694-4059-BE4F-192053BDB22F.jpeg

    The Patina

    The patina, and in particular the transfer patina on the upper reverse, originally sold me on this coin as ancient. The crusty outline of another knife on the reverse only forms when coins are fused together for thousands of years. The coloration from the picture was also believable for an ancient patina.

    In hand, the patina of this coin initially gave me very bad vibes. It looked glossy and had a smooth, pebbly texture to it. The patina on the reverse was very dark, almost black. This made be think that the coin was cast with a patina texture and painted over (or otherwise treated). This is not uncommon when counterfeit moulds are made from genuine encrusted coins. Bad feelings aside, I examined closer. If this was the case, then I should see ample evidence that there was no patina layer on the coin. There should also be a bunch of raised metallic bumps. On genuine coins, there would be no bumps because of the high standard to which the moulds were made.

    On the obverse, there is a section where the patina was broken away. Looking at the edges of this break revealed that there were two distinct layers of patina. This was verified be looking at the various design elements and seeing chips which revealed two clear layers. The dark patina on the reverse was problematic because it was roughly the same color as the metal. However, there were some slight greenish hues, especially on the knife outline, indicating the formation of hard malachite. The rough-ish texture on the reverse also does not appear to be metal when compared to the metal that is exposed. The exposed metal is smooth and has some pitting from corrosion, but no raised features.

    A trusted friend pointed out that the obverse had a location where the patina was “peeling”. On fake coins where the patina was accelerated, the patina is often soft or flakes off easily due to poor bonding with the metal. This was his concern. This is easily seen on the reverse of the fake 6-character knife.

    A04EA1A8-E3A1-4335-8EEF-58D99622A9E3.jpeg

    I tried picking off some of the patina with my fingernails, and the patina was amazingly hard. No crust at all has come off, not even dust-sized bits. This indicates that the patina is very well-adhered to the surface of the coin.

    So I examined the “peeled” area further. There was evidence that it had been vigorously cleaned with some very light scrape marks visible. There is a dirty halo around the interior of the “clean” area where the (metal?) brush could not easily get to. Perhaps someone had tried brute-forcing the patina off and gave up? There are also small areas of red patina in the metal in this clean area. This is the same patina that is on the reverse of the four-character knife, and I see this relatively often on Qi knives. This means that the patina reached deep into the metal, very much implying that the patina is indeed ancient.

    Some additional observations and potential explanations:
    1. There are two knife outlines on the upper reverse. Based on the placement of the outlines, they could not have been overlapping in the ground, and there are no knife designs that could have produced that singly. I do not have find-spot data, but I’d wager that the two knives in contact were separated by earth movement (earthquake, plowing, etc.) and then rejoined to form the second image.
    2. The patina is very glossy. Generally this is not a good sign, but the evidence of a harsh cleaning on the “peeled” area would explain the glossiness. The evidence of a harsh cleaning means that the patina well-bonded to the coin and is thus ancient.
    3. The black/dark patina, while uncommon, is not unheard of. I generally see it on Chinese coins with abused surfaces, such as the Qi knife pictured below.
    1BA8FFAE-9E70-4F83-A24B-EBB4A3DD776D.jpeg

    The Metal

    The reason why the consignor believed this coin to be a contemporary counterfeit was that an XRF analysis of the coin had the following results:

    Cu 15.6 %
    Pb 67.0 %
    Sn 10.7 %
    Fe 6.7 %

    In contrast, the genuine 4-character knife had the following results:

    Cu 66.3 %
    Pb 14.9 %
    Sn 17.1 %
    Fe 1.7 %

    However, in-hand, I can guarantee that the XRF results are not correct. There are areas where exposed metal was worn, and a brassy color was exposed (shown below, lower right rim). Qi knives are supposed to have a brassy color, and lead should have a more gray appearance. In addition, resonance tests further conclude that there is not a predominance of lead. I believe that the Cu and Pb results got switched between the machine and the inbox.

    F3C153C5-5DFB-4A2C-A10D-F11FDC6EEEF9.jpeg

    The resonance of the coin was testing by holding the coin as below, lightly tapping it in the middle and hearing/feeling the response. The 4-character knife had some resonance, but it did not ring much, which implies some crystallization of the metal. The fake 6-character knife hummed as expected because there was no metal crystallization. The subject coin has significantly more resonance than the 4-character knife, but also much less than the 6-character. From this, there is some crystallization of the metal. Exactly how much is very difficult to tell.

    DCB51E64-03D9-458D-A395-5830070BE64C.jpeg

    Conclusion

    The style is exactly what is expected when compared to genuine coins, and the patina has ample evidence that it is ancient and not cast into the metal. The resonance and observation of the color of the metal highly suggests that the XRF results are not to be trusted and that the composition is likely consistent with genuine knives. The comparative resonance between known genuine and counterfeit examples suggested that the metal was crystallized to some degree. With all of this said, I am concluding that this knife is fully-genuine. If there are any flaws to my logic, or if there is something I overlooked, feel free to tell me. I would like to know.

    The cleaning that made the patina look unnatural severely hurt the value of this coin. Collectors (like myself) prefer coins where authenticity is readily apparent (like in the lot of six posted above). However, after my analysis, I would be sufficiently confident in the authenticity to pay up for it if offered to me again. Since I have been wanting an example of this type for years, I am very happy. :)
     
  2. Avatar

    Guest User Guest



    to hide this ad.
  3. TypeCoin971793

    TypeCoin971793 Just a random guy on the internet

    Well, dookie. The pictures all disappeared

    EDIT: all fixed
     
  4. dougsmit

    dougsmit Member

    I hope they reappear. This will be a great post when they do.
     
    Curtisimo likes this.
  5. TypeCoin971793

    TypeCoin971793 Just a random guy on the internet

    They are back!
     
  6. Jwt708

    Jwt708 Well-Known Member

    An interesting write up for sure. I have nothing useful to contribute but I don't think your conclusion is out of line. Perhaps have another XRF test done? I think @Ken Dorney is knowledgeable in this area, maybe he'll render an opinion?
     
    Spaniard likes this.
  7. TypeCoin971793

    TypeCoin971793 Just a random guy on the internet

    I am planning to contact the respective facilities at my school to do just that.
     
    Curtisimo and Jwt708 like this.
  8. Ken Dorney

    Ken Dorney Yea, I'm Cool That Way...

    I posted a comment on it on Facebook, but for those here this coin looks exactly as it should and I would be surprised if it were anything but authentic. Tom has already given a perfect write-up.
     
    Paul M., Jwt708, dougsmit and 2 others like this.
  9. TypeCoin971793

    TypeCoin971793 Just a random guy on the internet

  10. Spaniard

    Spaniard Well-Known Member

    Great write up @TypeCoin971793 ......
    Its not a field I collect in but have learnt a great deal from your thread.....
    Wow! really appreciate the photo of the knife in hand which gives the unknown (to me) some perspective and now I can really acknowledge how much of an impact this coinage can have....Thanks for sharing your knowledge.
     
    TypeCoin971793 likes this.
  11. Paul M.

    Paul M. Well-Known Member

    Very interesting post. I understand evaluating the style and patina, and even the resonance of the metal (though I'd personally be afraid I'd break a fragile and rare piece doing this), but is XRF a standard step in authenticating something like this?
     
    TypeCoin971793 likes this.
  12. dougsmit

    dougsmit Member

    How large an area is sampled by XRF? It strikes me that the results from several small areas on a piece like this could be different and there is no reason to assume that an average of them would be more nearly correct than any single one. Is the surface corrosion on such a piece certain to be from the piece or perhaps from the environment so the sampled area need be from a bare spot? Can you summarize the process as applied to a coin like this?
     
  13. TypeCoin971793

    TypeCoin971793 Just a random guy on the internet

    They are very large and impressive coins, which makes them very popular. Their values have risen tenfold in the past 15 years, though they stabilized about 5 years ago. The lot of 6 knives mentioned above sold for a little under $200,000

    Light taps are all that is needed. They won’t break the coin. The ones that are the most fragile would be obviously genuine on patina alone.

    It isn’t standard until the value of the piece warrants it (like this one). Even then, usually that is only reserved for museums. All the XRF will tell you is if the metallic composition is consistent with genuine coins or not, so I would place a lot more evidence on the style and patina. The resonance is a step further if you are not 100% sure from the other two aspects.

    All I know is that the XRF analysis was done. I was not there, so I don’t know how. I know at my school our equipment is capable of analyzing large samples, so I can answer your question when I have the XRF analysis done.
     
    Paul M. likes this.
  14. TypeCoin971793

    TypeCoin971793 Just a random guy on the internet

    Here is a very modern fake of this knife. They did a fairly decent job with the sharpness of all the lines, but the rims and font are the wrong style. The characters seem laterally smooshed.

    The “patina” is literally just acid etching into the surface, giving it a fragile cancer growth look. The surface would just flake off.

    7CC8E829-8A7B-405B-A82D-78467C7314D8.jpeg 21FE33C5-7DDB-412B-A55B-CFCA7C5FAC07.jpeg 3BA58CF7-3A90-4A62-96A9-17CB84C79E29.jpeg
     
    Paul M. likes this.
  15. TypeCoin971793

    TypeCoin971793 Just a random guy on the internet

    I have an appointment with the GT XRF shop Wednesday! I will let you all know the results.

    The spot that was scraped away was likely done to provide an area of bare metal so that the XRF could get a proper reading since it can’t read through patinas.
     
  16. jj1361

    jj1361 New Member

    Very nice write-up @TypeCoin971793 Do you know by any chance what should be the XRF results for Kai Yuan Tong Bao coins? I have one which I tested and it has Fe (5%) , Cu (44%), Sn (21%), Pb (30%)
     
    TypeCoin971793 likes this.
  17. Ken Dorney

    Ken Dorney Yea, I'm Cool That Way...

    Unfortunately such tests wont tell you a whole lot in the long run (or short even). While studies have been done in a limited fashion, to be of general use many many thousands of coins would have to be tested to get any data of use for authentication. If one is interested in the topic, check out Metallurgical Analysis of Chinese Coins at the British Museum by Helen Wang. I used to have a copy, but it bored me to tears so I sold it. You can get a copy from Oxbow Books for a paltry £6.95:

    https://www.oxbowbooks.com/oxbow/ca...alysis+of+Chinese+Coins+at+the+British+Museum
     
    TypeCoin971793 likes this.
  18. jj1361

    jj1361 New Member

    Please check this kai yuan and let me know if patina and style is ok? I really have no idea on chinese coins and their patina
     
    Last edited by a moderator: Oct 30, 2019
  19. TypeCoin971793

    TypeCoin971793 Just a random guy on the internet

    Absolutely nothing wrong with it
     
    Last edited by a moderator: Oct 30, 2019
  20. jj1361

    jj1361 New Member

    Thanks @TypeCoin971793 I always thought patina on ancient bronze should be green but on this kai yuan it is dark with some pink hue on reverse which was a bit strange to me
     
  21. TypeCoin971793

    TypeCoin971793 Just a random guy on the internet

    It can be green, red, blue, pink, brown, tan, and pretty much anything.
     
Draft saved Draft deleted

Share This Page