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Fraudulent gold coins.
https://www.gemologyonline.com/Forum/phpBB2/viewtopic.php?f=38&t=23219
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Author:  Alan F. [ Mon Nov 07, 2016 8:41 am ]
Post subject:  Fraudulent gold coins.

Growing Fraud.

A new fraud I have seen is a number of fake Krugerrands. These coins, when genuine, contain 1 oz of 24 carat gold. I have been shown a counterfeit Krugerrand that is of excellent quality, correct dimensions, correct weight, correct density and the coating tests 24 ct with acid. The core, which gives it its density, is made of tungsten, which gives a reasonably easy test for genuineness. Balance the coin on a finger and strike the edge with something metallic, the genuine coin rings, the fake doesn't. The difference is quite striking. Good luck!

Author:  Barbra Voltaire, FGG [ Mon Nov 07, 2016 10:40 pm ]
Post subject:  Re: Fraudulent gold coins.

Brilliant observation! =D>

Author:  Alan F. [ Tue Nov 08, 2016 5:23 am ]
Post subject:  Re: Fraudulent gold coins.

Thank you for the compliment, but I cannot claim complete originality for the test, It is something my physics teacher showed me many years ago. I just applied it to tungsten.

Author:  wilsonintexas [ Tue Nov 08, 2016 7:44 pm ]
Post subject:  Re: Fraudulent gold coins.

I wish I A real one and a fake one to try it
I think we have an original from my uncle in the safety deposit box

Author:  ruby302 [ Wed Nov 09, 2016 11:27 am ]
Post subject:  Re: Fraudulent gold coins.

On the program 'pawn stars' the shop still buys gold & silver ingots but for years now uses a simple method of drilling into the item a little more than 1/2 the thickness at several locations, they were burned early on by people who filled the items with tungston bars, which is similar in weight to some metals & duplicate the marking on the ingots as ID for the metals. The drill holes are very small & the findings are fool proof, just about, with little damage or loss to the item. Once burned, twice shy! This can be applied to any precious metal item-buyer beware, now better informed- 8)

Author:  Alan F. [ Wed Nov 09, 2016 5:46 pm ]
Post subject:  Re: Fraudulent gold coins.

The drilling into the ingot test, whilst foolproof, requires one to have a drill and drill press handy. The sound test requires only a second coin, balance both on opposing forefingers, then strike one against the other and listen to the ring. You can do it with any coins and it is worth trying it to get the feel of the test.

Author:  gembug [ Thu Nov 10, 2016 1:48 am ]
Post subject:  Re: Fraudulent gold coins.

Interesting. I have two Canadian gold Maple Leaf coins, 1 oz which I tried this with (balancing each coin on my index fingers, then clinking their edges together with the coins in plane with each other).

Faint clinking vs. ringing. Trying a different test I tapped the rim of a coin balanced on my index finger with metal letter opener and heard more of a clunking noise rather than a ring.

In either case, I would hesitate to call it a ringing noise, though the first test with two coins definitely gave a high-pitched clink vs. a dull clunk. The second test was a clunk.

I have to assume the coins are real - purchased directly from a reputable coin shop some time ago. And I'm not about to drill into either to double check.

Can you elaborate a bit more of what you mean by ringing noise?

Thanks for the tip and excuse to play with the coins :)

-Allan

Author:  Alan F. [ Thu Nov 10, 2016 5:03 am ]
Post subject:  Re: Fraudulent gold coins.

If you get a different note from two coins that are supposed to be the same, it is definitely a reason for further investigation. See if you can find a dealer with an electronic metal tester. The fact that they came from a reputable dealer means little with fakes of this quality.

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