World silver coins and specific gravity test results

https://en.wikipedia.org/wiki/Trial_of_the_Pyx

The Trial of the Pyx (Pronunciation) is the procedure in the United Kingdom for ensuring that newly minted coins conform to required standards. Trials have been held from the twelfth century to the present day, normally once per calendar year; the form of the ceremony has been essentially the same since 1282 AD. They are trials in the full judicial sense, presided over by a judge with an expert jury of assayers. Trials are now held at the Hall of the Worshipful Company of Goldsmiths; formerly, they took place at the Palace of Westminster. Given modern production methods, it is unlikely that coins would not conform, but this has been a problem in the past—it was tempting for the Master of the Mint to steal precious metals.

 

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On the balance of probability, I think it is far more likely that numerous countries did make coinage of the specified composition, than they did not do so.

For a start, debasing the coinage would be such a political hot potato that for a relatively trivial gain, few governments would be willing to give their opposition such a potent vote winner, as provable debasement of the coinage done by stealth. When Britain debased the coinage in 1920, to 50% silver, and again in 1946/7 to no silver at all, it was a cross party decision in response to an obvious economic crisis due to the massive costs of WWI and WWII.

Britain has been very fussy about the correct assay and marking of all silver objects for many hundred years. You might try your tests on a British hallmarked silver object, such as a napkin ring or teaspoon, since it will have been assayed to check that it is 0.925 silver. Should your results indicate anything other than .925, I suggest your tests are far more likely to be wrong than any of the British assay offices.

 

I decided to do a bit of maths and I am a bit stumped. This is what I got when I calculated. Somewhat close for most of them.

Fineness Density
0.999 10.49
0.925 10.36
0.900 10.31
0.835 10.20
0.800 10.14
0.750 10.06
0.600 9.82
0.500 9.66
0.400 9.52
0.300 9.37
0.200 9.23

I think there are some key assumptions here. One is that this is an alloy of silver-copper and there are no other trace metals. Second is that as suspected, that mints were purposely reducing silver content despite what was mandated.

China and Korea in the past were notorious for this as whenever the price of copper shot up, they substituted it with other metals such as zinc, tin, iron, nickel, antimony etc. This practice has also affected silver coinage. I am not aware of any studies that have done on the silver alloy content so but there was definitely huge mistrust in the public because of poor mint practices in the late 1800s.

I'm somewhat suspecting that during financial difficulties, in particular WWI and WWII, mints may have done something questionable. As of what they may have done - it's definitely interesting to see some XRF results before any further speculation.

 

Here is the cheapest "used" desk top XRF I found so far... for those of you with deep pockets. Many more are available. This one struck me as it is a low price item, when compared to some of the other....WOW! This one needs a computer, (I think ) which is not supplied with this model, others come with their own computers.

 

Not only can the mint be suspected, but the suppliers! Think of the profits they can make if their 87% (for example) silver slips by and is accepted as 90% (Sunshine Silver et cetera). Are the mint assayer's paid well? How many tests are performed? On and on...

 

I was really tempted to put that in as well but I thought carefully before adding that it. If I am not mistaken, it was only quite recent that mints contracted suppliers for their planchets. I'm certain that even in the early 1900s, mints would procure all materials and did everything in house, from smelting to producing metal sheets. I remember someone posting a video of the US mint and it did feature the smelting process.

As of when it was more economically viable to procure planchets from external suppliers - that's another field worthy to be researched. I'm sure this also varies from various world mints. I suspect it would be around 1970s when global economy hit everyone's pockets and mints were forced to find ways to cut costs.

 

I must say, this is very interesting.
No XRF here, or I would be happy to run some tests.
I must say, I would suspect that if the debasement were so prevalent, something would have been written about it by now.
...Right?

 

OK, just a few more lumps to stir into the pot. I have done some SG tests over the years and one thing I learned was that distilled water and temperature control are a must for consistent results, along with the high quality scale. One other thing, have you tried comparing just the weights of the coins that came up with the wrong values with their required weights? I just looked up the U.S. half dollar as an example. A 90% silver piece weighs 12.5 grams (+-.25) and a 40% silver weighs 11.5 (+-.4). If your tests show a large variance in the SG of a coin, then there would be an equal difference in the weight since their volume should be consistent. Thoughts?

Joe Paonessa

 

Thanks Gxseries--for checking those figures against the math. In retrospect, I should have elaborated--some of those figures provided came from tables used by the jewelry industry. Those I calculated myself match yours; the discrepancy in others may be due to using actual lab results rather than pure calculation.

I do agree there are assumptions present. Even if our methodology is reasonably sound, SG tests simply can't tell you the composition. We might infer the debasing is due to copper, but we'll never be sure without an elemental analysis. Whether or not we dislike the idea of debasement in modern coins, I think we should admit there's a huge potential for monetary gain for doing so. And I think all of us know how much money drives things in our world.

All said--I'm not comfortable with discussing abasement in any detail based on simple SG tests. There are too many unknowns, coupled with the fact that I'm not a professional lab so my results aren't rigorously scientific--even if they suggest something is going on with silver coins. For that reason, I'm giving up with discussing SG in favor of elemental analysis via XRF. Thanks all for the stimulating discussion.

 

I guess my point is this--my gut reaction to a particular test should not be the basis on which I decide it's factual--or not. For example, during the Chernobyl reactor meltdown, when the workers tested the radiation levels, they were so high that the station director would not believe it. The numbers made "no sense" to him, even though they proved to be absolutely correct. Well that's an extreme example to simply suggest our reactions cannot always be trusted as factual...

Honestly, that was my first reaction when I tested these silver coins--I was very skeptical of the numbers. So I tested them over and over. Thinking about it further, I believe it was on the order of 6 times for those coins which showed a high disparity. But even though I'm an extreme perfectionist, I won't demand the readers believe in my work without any other supporting data--that would be just another fallacy. Hence why I'll focus on elemental analysis via XRF from now on...

I would only suggest there are more options than just two. Here are a few that come to mind:

• The govt mints did not assay every bit of silver coin stock provided by their vendors, so they're not actually aware of all purity errors.
  
• Some govts. of their respective mints do not like to "look bad", thus they would not divulge issues with coin purity--even when they knew them.
• Either a vendor, mint employee, or govt official was actively siphoning off silver for personal profit--and they knew nobody would check--although I agree this seems unlikely.
  
• The govt. had a (secret) policy of debasing silver coinage so they could direct the money elsewhere in times of financial crisis, such as during war.
• The govt is just typical of history as a whole--they bumble their way through things, hoping not to appear too incompetent. Thus, they don't scrutinize things too closely--despite what they say.
  
• Finally, perhaps we decide not to believe anyone without cause--and just see where the data leads?

Again, I consider this an interesting topic to pursue further, which I'll do when I find more XRF data. I suspect that as XRF analysis becomes more prevalent, the data is going to prove to be very illuminating.

 

I think we should admit there's a huge potential for monetary gain for doing so

For modern coins the gain would be trivial, in money, even compared with the profits they make selling modern coins to collectors, the only, and relatively small market for them.
Consider, also the potential downside when it becomes common knowledge, as the Volkswagon diesel emissions test is for VAG.

https://en.wikipedia.org/wiki/Metallurgical_assay

Many people have spent a lot of time assaying all types of precious object. I think if there had been any duck-shoving going on it would be common knowledge by now.

I'd bet 10 kilos of silver to a wooden nickel that in general (excluding what Borogrovia might have done in 1825, or other obscure occurrence), that silver and gold coins of the last 200 years have always had the legally mandated metal content.

 

Assay via XRF will be much more prevalent in the future--and all these silver coins are just begging for new analysis. Rather than hold to assumptions from the past, I'm going to wait and see what the XRF data says. XRF is even changing what we know about ancient Roman silver--and we've had centuries to analyze it.

 

Well...a few of these coins have been since sold, but I have other silver coins, if not the exact test specimens discussed above. An honest question--are you considering assaying coins yourself--or just asking me to do it? As I said before, I am not satisfied with SG testing for composition--which is why I'm moving on to XRF. So I have a lot of gems/minerals/coins that beg for XRF testing. If I can find a reasonably economical lab to get it done, I will consider it--and post the results on a new thread. Barring paying for my own analyses, I will post whatever XRF research I can find on coin composition--I'll be totally upfront about what I find, no selective bias.

 

For what it's worth, I've heard rumors for many years that some countries and some coins are not allthey are purported to be. This applies to things like some central American countries of the 20th century as well as small or backward countries further back. Some coins have terrible quality control and it's been said that low fineness Mexican can be much lower than reported, especially the .100 fine Pesos.

It's a little difficult to believe that this is widespread and affects a broad category of coins. This would explain why refineries often short dealers redeeming large quantities of world silver coin, though.

 

I think I've explained why I can't test these particular coins--many are no longer in my possession. I consider my SG tests fairly rigorous--for reasons I've already given. So at this point, assays of coins I no longer own is a non-issue and essentially does not prove/disprove anything.

Finally, you say that further tests are "for my benefit" but throughout this thread you have expressed doubts--while providing no evidence to the contrary. The way I see it, you're dumping your doubts on me, and asking me to do something about it--why is that my job? Don't you have the curiosity to assay a selection of silver coins yourself?

Like I said, I've said all I can about SG tests. Next time, I will present only data I find on XRF analysis. Thanks everyone for the discussion!

 

What is the 'methodology' you used to obtain the data? You don't mention the exact complete testing process you used and many simple SG tests are prone to error.

 

I could spend two pages describing proper methodology--which admittedly I left out in the interests of space and to focus on results. The concept is put quite simply--you weigh the coin dry with an accurate scale, then you weigh it suspended in water, and from that data you calculate the SG. Anyone who wishes to test the SG themselves can easily hit Google and find everything they need to know. That is, if you want to satisfy your own curiosity.