Options
Rare earth counterfeit detector.
keets
Posts: 25,351 ✭✭✭✭✭
Have you ever heard of such a thing??
We have one that my boss bought from a guy at a show, it's homemade and on first glance looks pretty hokey. It's about six inches tall, two sides hinged in the middle and one side has 3/4" x 2" metal strips that the Silver Dollars slide down. Genuine Morgan/Peace Dollars slide sort of slow, the counterfeits go down noticeably faster.
You gotta long the ingenuity of some people. 
Al H.
1
Comments
Sounds similar to “Dr. Doug’s counterfeit detector” – does yours say Dr. Doug anywhere on it?
Seen those. You can use a rare earth button magnet and tilt the coin. Fast slide, not silver. Slow slide, likely silver. Easy to take to the show or coin shop. Not perfect but better than nothing. Not for proofs or high grades as it may cause light scratches.
Yeah, a clever take on the idea of "rolling" small rare earth magnets down the face of a silver coin. They slide slowly on genuine silver, they slide fast on fakes.
--Severian the Lame
Yes. There is a scientific basis for this. There are potentially better designs that involve sliding the magnet instead of the coin, so as to not cause friction/damage to the coin.
IG: DeCourcyCoinsEbay: neilrobertson
"Numismatic categorizations, if left unconstrained, will increase spontaneously over time." -me
we use it on circs so damage is no worry. it is very handy when buying bulk since there really are a lot of fakes.
I imagine that if you get a lot of counterfeit rare earth, then a rare earth counterfeit detector would be good to have
Just don't put your wallet near it. Your credit cards will thank you.
The testing device uses a "rare earth magnet" which is extremely strong and can be used to test a silver bar. Silver is weakly magnetic when it's moving through a magnetic field. Tilt a silver bar at about 30 degrees and slide a rare earth magnet down it. If it's real silver it will slide noticeably slower than if it's a silver plated base metal. These magnets are available on eBay. There are several videos showing how to test silver using this technique on You Tube.
Worry is the interest you pay on a debt you may not owe.
"Paper money eventually returns to its intrinsic value---zero."----Voltaire
"Everything you say should be true, but not everything true should be said."----Voltaire
A quick explanation is that some metals are paramagnetic, meaning they become magnetized when exposed to a magnetic field and some are diamagnetic, meaning they are not affected by a magnetic field. Paramagnetic materials won’t jump to a magnet like iron or nickel, but when exposed to a strong magnetic field from a rare earth magnet it can affect the speed of an object sliding through it. So basically, your comparing the amount of paramagnetic elements in a the 90% silver alloy vs other alloys that could be in a counterfeit. Not a foolproof test, but since most counterfeiters aren’t physicists or metallurgists, you can probably catch a lot of fakes this way.
If any of the resident Physicists find something wrong with my explanation, please correct it. Usually, my Physics classes were at 8AM, which is a God-awful time of day for a college student (especially if you went to the bar the night before), so I know just enough about this stuff to make myself dangerous
The magnetic slide detects fake silver through an 'intrinsic property' known as diamagnetism. This produces an effect called the Eddy Current Brake
Successful transactions with : MICHAELDIXON, Manorcourtman, Bochiman, bolivarshagnasty, AUandAG, onlyroosies, chumley, Weiss, jdimmick, BAJJERFAN, gene1978, TJM965, Smittys, GRANDAM, JTHawaii, mainejoe, softparade, derryb, Ricko
Bad transactions with : nobody to date
slide starts at 2:45
https://youtu.be/3gUjuS5TzwI
Successful transactions with : MICHAELDIXON, Manorcourtman, Bochiman, bolivarshagnasty, AUandAG, onlyroosies, chumley, Weiss, jdimmick, BAJJERFAN, gene1978, TJM965, Smittys, GRANDAM, JTHawaii, mainejoe, softparade, derryb, Ricko
Bad transactions with : nobody to date
I love this kinda stuff. This is why I check the forum every day. It's a box of chocolates, you never know what you are going to get.
Problem is that some of the chinese fakes are 90% silver. And the ones that aren't you might as well just ring
But...............We always need to try and build a "better mouse trap"
Successful transactions with : MICHAELDIXON, Manorcourtman, Bochiman, bolivarshagnasty, AUandAG, onlyroosies, chumley, Weiss, jdimmick, BAJJERFAN, gene1978, TJM965, Smittys, GRANDAM, JTHawaii, mainejoe, softparade, derryb, Ricko
Bad transactions with : nobody to date
Search ebay for neodymium magnets and you'll find all you want. Mine are about 1/2" across and 1/8" thick (round) and work great.
bob
You can buy them prebuilt on the bay, here's a listing for one...
https://www.ebay.com/itm/Magnet-Test-Coin-Slide-Granite-Budget-Slide-Check-Fake-Silver-Coins-by-YouTube/183940816858?hash=item2ad3ba1fda:g:sx8AAOSwOIxc20so
There are a couple of YouTube video of a copper/zlincon coin sorter using this principal...
ANA 50 year/Life Member (now "Emeritus")
Good free rare earth magnet can be pulled out of hard drives and microwaves. Peace Roy
BST: endeavor1967, synchr, kliao, Outhaul, Donttellthewife, U1Chicago, ajaan, mCarney1173, SurfinHi, MWallace, Sandman70gt, mustanggt, Pittstate03, Lazybones, Walkerguy21D, coinandcurrency242 , thebigeng, Collectorcoins, JimTyler, USMarine6, Elkevvo, Coll3ctor, Yorkshireman, CUKevin, ranshdow, CoinHunter4, bennybravo, Centsearcher, braddick, Windycity, ZoidMeister, mirabela, JJM, RichURich, Bullsitter, jmski52, LukeMarshall, coinsarefun, MichaelDixon, NickPatton, ProfLiz, Twobitcollector,Jesbroken oih82w8, DCW
Interesting sorting method....I have read about it before, but the video is good instructional material. Cheers, RickO
I think they are in some power tools also