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View Full Version : Beware: Fake Gold Bars!



Marshall/Ak
09-20-2012, 08:39 AM
Be wary of investing in gold bars:

http://www.myfoxny.com/story/19578206/fake-gold-bars-turn-up-in-manhattan

Reno Chris
09-20-2012, 09:40 AM
Yikes!
A quick way to check this would be with a portable XRF tester. Would take only seconds and you'd see the tungsten without opening up the bar. I imagine that these will become standard for gold bar buyers.
(For more info on XRF guns, see the next issue of the ICMJ!)

Chris

overtheedge
09-20-2012, 11:10 AM
Ran into an article on the web about phased-array ultrasound testing that works perfectly every time. Non-destructive and fast. Seems tungsten has vastly different scattering characteristics than gold.
eric

Steve Herschbach
09-20-2012, 12:22 PM
http://cf.mp-cdn.net/a7/cc/f6fcae604ab932a8c4922e585284.jpg

geowizard
09-20-2012, 02:59 PM
XRF spectrometers are great tools.

However... Xrays have limited penetration in things like "LEAD". That's why they use lead shielding. :)

So... depending on the energy of the Xray i.e. 30Kev, xrays will penetrate lead .02 mm. Gold is penetrated less!

.02 mm = 20 microns. The (new) Niton handheld XRF is advertised at 50Kev.

Ref: http://www.sprawls.org/ppmi2/RADPEN/#PENETRATION VALUES

- Geowizard

P.S. "I could do anything if it weren't for the laws of physics."

geowizard
09-20-2012, 03:24 PM
I'm with ote on ultrasound. Metal (wall) thickness gauges have been around quite a while. Check these out:

http://www.checkline.com/wall_thickness_gauges/?referrer=adwords

It only measures wall thickness.

- Geowizard

Brian Berkhahn
09-20-2012, 05:33 PM
Interesting, a few years ago there was a story going around that the U.S. made a payment to China in gold.. only it was Tungsten bars with a gold covering and these bars came right out of Fort Knox.