Magnet test and ring test

Discussion in 'Silver' started by Alloy, Dec 31, 2018.

  1. Alloy

    Alloy Active Member

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    Hi all -- I need your help understanding some of the tests of silver authenticity I'm seeing on YouTube.

    People let a little magnet slide down an inclined coin or bar. I've only seen successful tests for some reason. The magnet slides down at what I'd call a moderate speed. Okay, so what's going on there? What does it do if it's fake? Couldn't fakes vary in their composition, or do they tend to be made of the same cheap metal? What's the fake metal for silver? (All I know is tungsten is the fake for gold, because they're almost identical in density, but nothing is almost identical to silver's density to my knowledge.)

    So the ring test is people dinging a piece of silver against something to see how it sounds. Are you well acclimated to this test and what kind of ring it should make? Is it easy to hear? What do you ding the silver against? Other silver or some kind of common coin? (I've downloaded an Android app that is supposed to test the ring, but it doesn't do anything on my phone...)
     
  2. Ag109

    Ag109 New Member

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    The magnet sliding test is a roundabout way of testing the conductivity, the more conductive the sample, the slower the magnet will slide. Silver has very high conductivity but copper is not far behind and you probably wouldn't notice the difference unless you had a magnet slide (lots of strong magnets with alternating poles) and a genuine sample to compare it with.
    Some fakes are steel and the magnet will stick, some may be brass or tin/lead alloy to get the density right but the magnet will slide off these quickly, plated copper will be hard to tell by the magnet test but the density will be different.
    Molybdenum has a density very close to silver but I dont think its common in fakes.
    This is all assuming .999 silver as alloys, stirling, 0.9 etc can have much lower and more variable conductivity and magnet slide rates due to the alloy components.
     
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  3. Eureka Moments

    Eureka Moments Well-Known Member Silver Stacker

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    For the ring test use a 10oz bar and hit yourself in the side of the head. Try the same with a fake. You should be able to notice a difference in the ringing sound inside your head. If you can't tell the difference at first have a few more goes and then you should be right. For best results regular practice helps. :)
     
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  4. SlyGuy

    SlyGuy Active Member

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    Ring and magnet are both good and easy basic tests to know. Ring test is especially important since you can do it anywhere.

    Ring test works well with silver... works really really good with gold coins (they ring even longer and higher). All you do it hold one on your fingertip (so it can wobble) and hit it with another coin. You will hear a high pitched and long lasting ring (much longer than a regular clad coin)... unmistakable once you get accustomed to it. If you have bad ears, try The Ringer (by Fisch company) or try the apps on phones or computers that can supposedly detect frequency. I just use the coins.

    Magnet slide test is better for bars or large coins, but it is also impossible to mistake once you learn it. You need the coin or bar at an oblique angle (roughly 45deg... I use a scrabble game wood letter holder). You put a neodymium magnet on the silver at the top and watch it slide down. Every other metal will slide down fast or stick the the coin... a silver coin will have the magnet slide sloooooowly.

    Here's the basics... shows the ring and magnet tests well:



    ...personally, I just carry a small $5 digital scale and a real version that I own of the coins I might buy (usually just ASE, maple, gold sov) when I go to a coin show or shop, etc planning to buy coins. That is all you need once you know the tests. The scale lets you do the weight test (better than a Fisch type thing), and a known real coin covers the side-by-side comparison test, the size diameter and thickness exam, and the ring test. I honestly don't usually bring any testing stuff at all when I just make impromptu stops into pawn shops or coin stores I know to have consistently sold me good stuff many times, though... I just trust them to screen what they buy... and I look close at the coins, ring it, and then test it when I get home. I feel pretty confident these places would rather keep my business than take my $100 or whatever by not accepting a few bad coins back if my home test showed them to be suspect.

    I also have a Fisch type device for gold coins, magnet for silver, old antique brass sovereign balance (actually works badass), etc for doing more testing at home if I'm ever unsure. I guess I would bring the gold 1oz coin tester to shows if I ever wanted to buy 1oz gold, but I don't tend to see very good deals on that at shows and usually just buy that from major bullion dealers (that usually makes high enough order $ for free shipping on everything).

    I've seen a few ASE fakes (failed weight, or easy to tell detail was not right on comparison), but I've never bought fake coins. If there were some coins that the dealer/seller wouldn't let me take out of the capsule (I've never run into that issue), I'd just pass... not into numi stuff anyways.

    No one test by itself is the gospel, and they must be used in conjunction with one another...

    Keep in mind that silver (non-numi) is barely even worth faking right now. Still, it has high volume of sales, so fakes do exist... and will probably get more common if spot price goes up. The vast majority of silver fakes will fail on weight. Some will fail on size. All will fail on ring. All will fail on magnet test unless they are mainly silver... so not worth faking that way with spot low. Most will fail design comparison test.

    Gold fakes that are tungsten (or platinum if gold passes platinum) yet gold plated will only fail ring test (they can pass weight and size and maybe even cursory design comparison exam). Gold fakes that are a lesser % gold... ie 14ct or 18ct faking 22ct or 24ct coins may pass ring and weight yet fail on size testing and possibly design comparison. Gold fakes that are "jeweler copy" of same 999 or 917 gold content but not the original minting are tough and only detected by trained person doing design comparison. But again, I don't give a crap about those jeweler copies since they're not a problem to me... I'm buying the gold near spot and not paying premium for numi value anyways. The people trying to pass those off as high premium numi old gold coins will be selling for high prices and I wouldn't even be looking at them. If you want to do older numi gold, you obviously need great eye for detail, comparison, loupe glasses, etc etc.

    ...if there is ever any doubt, just don't buy it. There will always be more for sale. You never lose anything by not buying (PM or otherwise). GL
     
    Last edited: Jan 3, 2019
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  5. leo25

    leo25 Well-Known Member Silver Stacker

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    i did a test regarding the sound of silver coins a while ago if you want to have a look.

    https://www.silverstackers.com/forums/index.php?threads/1-oz-kangaroos-weigh-slightly-more.72363/
     
  6. Bullion_ron

    Bullion_ron Well-Known Member Silver Stacker

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    Good ol' percussive maintenance testing
     
  7. bijeco

    bijeco New Member

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    I recently bought some coins (1 of each of some of the most common I like) and the ping test wasn’t very conclusive ! I bought a silver eagle, maple, kangaroo , kookaburra , krugerrand and an abc eureka round , all 1 oz silver. The kookaburra was in plastic so no ping but only the silver eagle and krugerrand sounded good .. the rest were a dull noise with no lingering “ping” sound ! I doubt they’re fakes as I bought the lot from jaggards and abc bullion in Sydney
     
  8. bijeco

    bijeco New Member

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    I even put them on scales .. my scales are prob not the best but they all weighed between 31.23-31.54 g .. i even checked their diameter with very accurate calipers and they were perfectly inside of their published size ! I guess the ping test is only good for eagles, Kruger’s and from what I’ve read philharmonics

    As far as magnet test went I used 2 20mm neodymiums one on top of the other with the coins at about 45 deg angle .. they seemed to slide down the coins somewhat slowly but not nearly as slow as they did on the 10oz cast bars .. I assume this was because unlike the cast bars the coins have raised ridges and are a much smaller mass .. I’ve ordered 2 5mm magnets too to make a more accurate test of it
     
    Last edited: Jan 20, 2019
  9. leo25

    leo25 Well-Known Member Silver Stacker

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    The lingering ringing sound doesn't happen on all silver coins, so you shouldn't use that to test if a coin is legit. Every coin has it's own sound profile, the slightest thickness, width or design difference can change how a coin sounds.
     
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  10. SlyGuy

    SlyGuy Active Member

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    No one test works by itself... you need to use them in combo.
     
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