xrf analysis

[occnumis2021]

anyone out there ever done or had one done on any coins?

i've asked kinda shop owners over the years (a few diff ones) to scan various coins, mostly counterfeit related and here are the blurry results from a couple of those tests.

scan-cbh-2015.JPG

[MintErrors]

It's a legit process but, I would like to know how deep the testing does go.
If it's a surface analysis, does it detect a counterfeit core ?
I believe a lot of the TPGs have this capability.
I am not sure which units are accurate and how pricey they are.

[occnumis2021]

It's a legit process but, I would like to know how deep the testing does go.
If it's a surface analysis, does it detect a counterfeit core ?
I believe a lot of the TPGs have this capability.
I am not sure which units are accurate and how pricey they are.

at the time iirc, they said the units they had were several thousand dollars at least but a pittance to the prevention of buying fakes but also to check them expediently as some shops have non-numismatists working their counters, good enough to know about spot prices, weights etc but not really authentication and even some people with that experience need further methods to be safe.

for all the testing they did in front of me for many customers and the few items i asked them to scan, they seemed to be spot on but i'm not saying they will catch everything. a bit of trial and error would clear that up really quick, sorta like dialing in a metal detector or something.

just curious how many here have done it or seen it done in front of them. hopeing for a good conversational starter.

i've had scanned, white metal fakes (german?), aluminum, silver, antimony, lead etc.

[TR137]

XRF does not go deep enough to be your only test. Stuff thats gold plated usually uses as little gold as possible to achieve the color. It usually catches those, but it is possible to plate something thick enough to fool XRF. You always need some combination of tests. Sigma, ping, scale, magnet, specific gravity, specific heat, etc.

You can buy a broken XRF on ebay and fix it yourself, usually with a new rad source for like $2k. You can make your own from an x-ray tube, high voltage power supply, and usb gamma spectrometer for like $1k.

You can also get an XRF outside the USA from aliexpress for like $300, but you will need to add your own shielding and I don't know how you'd get it into the country legally or otherwise.

[occnumis2021]

ya, those sigmas are other types of detectors i've seen dealers have at shows if it is what i'm thinking about. very portable.

i personally would steer people away from the "ali" sites. very risky imo. some good products i'm sure and a lot of bad ones, i'm sure.

[TR137]

ya, those sigmas are other types of detectors i've seen dealers have at shows if it is what i'm thinking about. very portable.

i personally would steer people away from the "ali" sites. very risky imo. some good products i'm sure and a lot of bad ones, i'm sure.

I'm not recommending building your own XRF or buying one from there. I only mention it because some people will, and PSA they lack shielding and will expose you to an unsafe dose of x-rays.