I didn't do the analysis myself, but I suspect that XRF is the least destructive method--chemical tests for silver would leave some damage.
I fact-checked the reference to "Babbitt Metal"--the composition of the counterfeit is very close to a common bearing alloy used today.
The author of this analysis, Rasiel Suarez, has directly given me permission to publish this article on CoinTalk. The author's full title is "A...
That table on silver fineness, and how it relates to SG, is well-known in the metallurgical/jewelry industry. These are consistent,...
While I think SG testing is fairly straightforward (if you have an accurate scale and good methodology), instruments which can measure actual...
I use a Nikon D810 body with a 60mm micro lens. When I shoot, the camera is on a copy stand and controlled remotely by computer software to...
If you're calculating differences in expected/reported data, you should use the specific gravity figures, and not the interpolated silver...
Well...the XRF will have to wait--I'm sure it still costs more than my fancy camera setup. :) I haven't sold any bulk silver coin to big outfits,...
I agree--finding varieties like this are a lot of fun. I found the currently oldest trail-dies coin. It's just fun and interesting--not that it's...
Well...'home lab' is my way of saying it's DIY--with some precision. That said, I used a calibrated, gemological-grade scale to calculate the SG...
Update: here are some XRF results for ancient and modern silver coins--source here. There is one US coin included, which has a significantly lower...
Agreed--that is a higher tech solution and you would know the exact metals/percentages involved. I will do a search and see if any...
That's a nice error on a US quarter! I have a few Canadian cents like this--it was pretty common on some years.
Gary, yes--you also tested that proof silver, 2014 Great Sand Dunes quarter. The SG result was only 10.16 , which suggests a silver content closer...
Tarnish wouldn't affect it by much if any fraction of a %, but I strove for standard results. :) All told, the discrepancies for silver coins...
Has anyone ever performed specific gravity tests on their coins? A while ago, I did a slew of tests and found the results very interesting,...
I wasn't a naysayer as much as trying to figure out the reverse die and MM position. I stand corrected on my suspicions--it was an educational...
Actually, I think it's pretty lousy behavior to launch into a tirade impugning the motives of other members simply because you don't like the...
The example above on the 1877-CC 25c is a repunched date--a completely different animal than a doubled die. During this period at US mints, the...
That may well be true--but at the onset, who can tell if someone is asking questions to learn, or simply playing a mind game? So there's no harm...
Separate names with a comma.
