Russ Bega wrote an article about a coin that crossed our paths at Harlan Berk. Years ago, it crossed @Insider desk as well. If you'd like to read it: article - Counterfeit, He Wrote
Having been one of the experts to examine the coin I can tell you this: it was a REALLY good fake and I don’t think anyone knew for certain until we had the coin analyzed via xrf. The composition wasn’t correct, even though it weighed almost exactly what it should have, but the Mint would never put platinum in a silver quarter planchet. That was the moment we knew, and I’m pretty sure we were the first to know for sure.
Do you mean palladium, not platinum, that was around the 3/4% mark? That is what the story said. But still would never be that high. I don't know how reliably XRF gets the bulk composition, but shouldn't genuine coins be very near 90.0% silver 10.0% copper? That composition seals the deal as a counterfeit.
Interesting story. Thanks for posting. The U.S. Mint (government, secret service) aren't experts? They said the coins were legit. Either palladium or platinum doesn't matter...neither belong in a 1934 quarter planchet. The real question is how did the U.S. Mint miss this...the Mint is quoted as saying the coins were legit??? The answer to this question was not addressed in the article (sorry if I missed it).
I said "TPGs/experts" because as far as I know, some of the ones they submitted to (ANA, INS, Coin World) aren't technically TPGs, just "experts". The part where "laboratory analysis by the U.S. Secret Service" deemed them genuine is pretty damning. I'm curious if there's something normally made with silver, copper and palladium that the counterfeiter could have melted down to make the planchets. It seems like an odd alloy to use.
I've followed the story of these for some time. In my opinion they are genuine, not "counterfeit". The XRF test is likely inaccurate, and the testing device margin of error was probably greater than the percentage of Pd/Pt reported.
I can tell you for fact that the likelihood of the xrf being wrong is very small. It was a major refiner here in Chicago that did the analysis for us.
If someone has one of these supposed "counterfeits", it would be worthwhile to make another close examination of it.
Do you have better images of it than the ones in the article? One option of course is that you and the Secret Service both got the same composition results, and for whatever reason SS didn't want to say why they exist. But then you'd have to explain why the mint was experimenting with 97% silver and put palladium in too. Was counterfeiting using real silver that much of an issue that they thought about making the quarters more intrinsically valuable? Going from 90% to 97% would hardly make any difference. From what little I've read, palladium can inhibit tarnish, but less than 1% isn't going the do anything for that either. On the other hand, if you're faking these for collectors, why so much silver and also add palladium? Which gets back to my question about whether there was something readily available that already had that composition.
There are multiple ways to do XRF. There are handheld instruments that shoot a quick pulse of high energy x-rays at the coin. The impinging x-rays will displace some orbital electrons in the metal atoms. When the orbitals refill from lower energy orbitals or the circulating crowd of electrons passing among metal atoms, characteristic (i.e. specific energy), x-rays will be emitted. These are detected, and their energy evaluated as they hit the detector in the instrument. The sum of these evaluations constitutes a spectrum of return intensity versus energy with peaks representing the characteristic energy of the orbitals of different elements (i.e. different metals). The software in the instrument analyzes the peaks and produces a readout of the percent of various metals. Another way to displace inner electrons from their orbits is with a beam of subatomic particles. For XRF, this is usually done with a scanning electron microscope (SEM) which shoots a beam of electrons at the metal in a vacuum and then evaluates the spectrum of emitted x-rays. One advantage of SEM compared to handheld x-ray devices is the electron beam can be focused on a very small (submicron) area. This allows multiple sites on the surface of a coin to be analyzed. So, for example, if a coin was suspected of being gilt but there appeared to be a few small spots of exposed underlying metal, these could be analyzed. The one time PCGS had a coin analyzed for me, it was done by SEM with 5 different sites on each side analyzed. And yeah, the original slab label was wrong, which is another story. XRF is primarily a surface analysis tool. Usually, gilt coins will return the same spectrum as solid gold coins. Very powerful x-ray-emitting lab instruments or SEMs can digger deeper, but it’s still pretty shallow. The problem is not the ability of high energy x-rays or electrons to penetrate, it’s the ability of the characteristic x-rays, which are of lower energy, to get out and be detected. Cal
