In the UK we already have the opportunity to buy PM's using fake currency and I would guess its not just the UK. This is Royal Mint info so reality is probably nearer 20% fake... http://www.royalmint.com/discover/uk-coins/counterfeit-one-pound-coins Keep stackin'
VicBitter---You hit on something important there. The source that you buy your PM's from is everything. eBay = forget it! Good, respected, established local coin shops and respected, known dealers at established shows and solid national-level high-end online dealers are OK. My buying is limited to 2 local shops, 2 show vendors and 1 online dealer -- and out of that group, 1 local shop and the online dealer get 90% of my fiat. There's an extra layer of insurance there that can't be found elsewhere.
Yes of course, any mass, even air, affects accuracy. The question is if it does in such a degree that the error is not acceptable. Packaging plastic is thin and mass is a fraction of metals. I just saw on discovery channel (why I revisited this topic) that series that searches for the valuable materials in shipwrecks, it was about 1 with supposedly alot silver bars. I could read a part of the name of the handheld analyzer they used, and along the web I identified it: company: Thermo Scientific product: Niton XL3t XRF Analyzer. Couldn't find a price though, only a service where they said they used this device and charge $59 to test a sample you send them. In the tv series, the bars turned out to be not silver. They struggled to test the bar, it 'didn't work' due to the outer layer / corrosion (probably it just said no silver and they doubted it), so they took a saw. No silver. Then they searched for a crew member that had some silver, and there it worked (68% jewelry). The bar was some alloy with copper.
A Perth Mint certicard 1oz gold bar will only read about 98% when XRFd in the card. Will read 99.99% out of the card. Reference - personal experience.
Certified silver is just another business strategy for dealers. It's not worthy to pay for paper, keeping in mind most dealers will have in house ultrasound and X-ray testing for all transactions to make sure they don't buy fake silver. You can also check for free in any jewelry for free, just go there with your recent silver purchase, and tell them you wanna sell, they will check for you... if fake just sue your dealer and get your fiat back to buy real silver. If real, just say you are not happy with the fiat they offer for your silver, and take your silver with you.
My dealer/s test all secondhand items before selling so no need to return for testing after buying. Can also get items bought from third parties tested for a small donation. This is in Melbourne, its a good place to build up friendly relationships with people.
That means that the card material occupies 2% of the material within the scanners reach, which means that the scanners measurement 3 dimensional zone must be quite small. I then wonder how they measure scrap accurately. These may have an outer corrosion, paint, dirt, moisture, whatever layer causing the same problem. And what about tungsten inside gold. Do these handhelds actually work on any thicker object? Or does it need to 'go around' the object along various angles as to test it in each direction?
Yes it's only a small field that it measure Scrap gold is measured on a couple of different places , if it looks suspect There is jewellery out there that is made to fool XRF machines NO XRF can not measure any deeper , it's enough to measure plated jewellery XRF's are NOT fool proof , you need a good eye & a little bit of knowledge to pick a fake I saw a 1kg silver bar earlier this year which just screamed "FAKE" without even testing it And yes it was a fake when it was tested
You need ultrasound instead of XRF to check deeper... But how about XRF's negative effects on health?
