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another Trade Dollar Authentication Tool

kazkaz Posts: 9,052 ✭✭✭✭✭
I recently ran across Lance's thread about using a reflector to photograph the reeded edge of coins in order to count the reeds. Having studied a few fake trade dollars, I know that the forgers don't put much effort into the quality of the edge reeding (or maybe it is technically too challenging to get right). Studying the edge with a loupe is pretty taxing, and standard edge on photos have very little depth of field so you can only see a small portion of the edge.
I found a cheapo flashlight in the junk drawer and pulled it apart. Then I photographed a fake and a genuine trade dollar inside the reflector. It just took a couple of minutes and the images were great. Here are enlargements of parts of the images:

Genuine:
image
notice how uniform the cross sections of the reeds are, and how smooth the grooves are. Inside most of the grooves is a single linear mark, not sure if raised or incuse, from the edge of the "teeth" of the collar, I think.

Fake:
image

You can see how the reeds are poorly formed, and the grooves aren't smooth with a lot of granules in them, and no linear mark along the length of the groove.



Comments

  • sparky64sparky64 Posts: 7,025 ✭✭✭✭✭
    That is some outstanding work, kaz.
    Well done and thanks. image

    "If I say something in the woods and my wife isn't there to hear it.....am I still wrong?"

    My Washington Quarter Registry set...in progress

  • tlake22tlake22 Posts: 299 ✭✭
    I'll be the moron, but don't see any difference.
  • crypto79crypto79 Posts: 8,623


    << <i>I'll be the moron, but don't see any difference. >>



    Depth, uniformity and the tappered beveling on the ends. The edge is actually a major tool for all counterfeit detection as the 3rd die (collar) is often an after thought . Well illustrated Kaz!
  • lcoopielcoopie Posts: 8,692 ✭✭✭✭✭
    if I understand it correctly
    you could have used a mirror to do the photos also??
    LCoopie = Les
  • lcoopielcoopie Posts: 8,692 ✭✭✭✭✭


    << <i>if I understand it correctly
    you could have used a mirror to do the photos also?? >>




    having read Lances thread I understand now, whats needed is a curved mirror


    well done
    LCoopie = Les
  • OriginalDanOriginalDan Posts: 3,713 ✭✭✭✭✭
    Nice illustration of the differences Kaz. Also a great way to perform reed counts.
  • kazkaz Posts: 9,052 ✭✭✭✭✭
    Thanks for mentioning the tapered beveling, crypto, it's very prominent on the genuine one.
    Just setting the coin in the reflector and looking through a magnifying glass gives you a good look at the reeds too, although I am not sure how this would go over at a dealer's table at a show!
  • 123cents123cents Posts: 7,178 ✭✭✭
    Well done Kaz and thanks!
    image
  • LanceNewmanOCCLanceNewmanOCC Posts: 19,999 ✭✭✭✭✭
    .
    1. great clarity!
    2. good work!
    3.

    << <i>I know that the forgers don't put much effort into the quality of the edge >>

    - this is one of the main reasons the mint started making edge devices/lettering.

    4. a large sampling is needed for each date/mm due to large variances i've found within a year/mm of reed count/sizes and distances/thickness etc. although the lower the estimated mintages, the less collars, the easier to use this method for authentication. if someone were to write a book to cover the most counterfeited coin types/dates/mms with edge devices, the reeds could be a very good tool if the information was correct and presented properly/effectively.

    5. thanks for making this thread. you made me think that maybe i should be using my point-n-shoot in lieu of my dslr because the dslr lens gets far less depth of field causing blur in my reeded edge study images. i'd rather not have to image/focus stack for this study.

    here is my comp. to make it easier to see the differences. i have to keep it simple for my mind to process the information appropriately/effectively.


    image

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  • thebeavthebeav Posts: 3,744 ✭✭✭✭✭
    That's excellent.
    Sometimes you just forget about the 'third' side of the coin......
  • kazkaz Posts: 9,052 ✭✭✭✭✭
    Thanks for the side by side images, Lance. Much more effective that way.

    How about this: what if you could ask for a "reflectorized" view of the edge of any coin when imaged by PCGS? It would also provide an interesting way to look at coins with lettered edges.
  • TennesseeDaveTennesseeDave Posts: 4,737 ✭✭✭✭✭
    I have a question. Why do some coins have reeding that goes all the way across the edge and some have a narrow strip of reeding just in the center?Both on genuine coins(Trade $'s)
    Trade $'s
  • NumisOxideNumisOxide Posts: 10,984 ✭✭✭✭✭
    Very nice tip!
  • Type2Type2 Posts: 13,985 ✭✭✭✭✭
    Nice good info. image


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  • stealerstealer Posts: 3,968 ✭✭✭✭
    Another note: most date/MM of this series have very strong rims as Kaz said. However, most of the 1875S have extremely beveled edges due to poor quality from the mint.
  • kazkaz Posts: 9,052 ✭✭✭✭✭
    Good info, stealer, I didn't know that. I also don't have an explanation for T.Dave either. Dave, have you noticed if this is common on coins of a particular year, from a particular mint?
  • stealerstealer Posts: 3,968 ✭✭✭✭


    << <i>Good info, stealer, I didn't know that. I also don't have an explanation for T.Dave either. Dave, have you noticed if this is common on coins of a particular year, from a particular mint? >>


    I didn't see his question before, and I would gander that he is referencing the 75S coins. Usually the narrow strip is even more pronounced on well-worn coins.

    Here's an interesting 75S: Rim Shot

    The reeding on the left runs all the way to the edge and practically falls off, whereas the right side is beveled. This is a genuine 1875S 1/2.
  • kazkaz Posts: 9,052 ✭✭✭✭✭
    Now I'm looking at a 75-s 1/2 that shows exactly the same thing. The rim seems to be beveled down creating a narrower area of reeding. This seems to go most of the way around the coin. and the rims don't look filed.
  • lostincoinslostincoins Posts: 4,278
    could you post a pic of your mock up?
  • greghansengreghansen Posts: 4,301 ✭✭✭
    I'll be the moron, but don't see any difference.

    Thank you for the honest reply. Not moronic, just inexperienced at this issue.

    In fact, the differences literally jump off the page at you if you have much experience at all in differentiating genuine vs. counterfeit Trade dollars. Excellent illustration and description by OP.

    Greg Hansen, Melbourne, FL Click here for any current EBAY auctions Multiple "Circle of Trust" transactions over 14 years on forum

  • kazkaz Posts: 9,052 ✭✭✭✭✭
    Hi John, if you go to the linked thread in my first post you will see the setup photographed by Lance. The coin is placed flat in the reflector which is then positioned under the camera, which is mounted on a camera stand as for a standard coin photo. hope that helps. Thanks for all the positive remarks, folks.

    I made some images of a 75-s because of the narrow reeding mentioned by some of the trade dollar specialists on the forum. As you can see from the closeups the ends of the reeds are truncated by a beveling of the rims, so instead of having pointed ends the grooves have open squared off ends. Only in a few short segments around the circumference of the coin does the reeding have the expected tapered/pointed look. As I recall, prior to striking, planchets went through an "upsetting machine" which raised the rims. So I can only conclude that the beveling is from the dies themselves. It would be interesting to see if this is found on 75-P's also. At any rate, a lack of "pointy" reeds or the presence of "narrow band reeding" does not necessarily mean the coin is a fake.

    In this obv. image, you can see normal reeds at the bottom, progressing to cut-off reeds as you move upwards.
    image

    The rev image shows a group of cut off reeds from the rim beveling. Note the tiny parallel striations inside the grooves, which I have not seen on fakes. Also note that the thickness of the "lands" remains very uniform
    image

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