testing silver coins.... help

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LH
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testing silver coins.... help

Post by LH »

I have a "the new millennium group" "one troy ounce .999 fine silver" that weighs 1.1 troy ounce (34.2 grams) instead of one troy ounce. A ten percent difference.

https://www.ukbullion.co.uk/productDetails/2273

this site lists its gram weight as 31.1 grams. Versus the 34.2 grams my scale says it weighs.

I tested it with nitric / HCL acid. initially on the side, it did not react, then barely started reacting (versus another coin, which on its side rapidly reacted), on the front, it reacted pretty quick(which surprised me, I thought it wasnt going to react), leaving the typical spot.

1)Just a priori, is it possible to have a one ounce silver coin that is real, yet weights 10 percent more???? seems like a heck of a discrepancy? I thought maybe 999 percent silver does not mean 999 percent silver, and it had some other metal mixed in, but the site lists its weight as 31.1 grams, and its actual gram weight is 10 percent greater.

2)does silver polish remove the acid stain to any extent?

3)has anyone tested silver better with acid? are there better less destructive methods, maybe scrape some on a stone, then put on a qtip, then put minimal acid on qtip or something? might react with qtip, dunno.

I hate to mark up the coin further, but it seems so weird it would be 10 percent overweight. Maybe plated? Just want to get some input before I file it or chop it in half out of perhaps misguided curiosity.

Thanks,

LH

Edit:
These are not numismatic coins, just melt value one ounce bars/coins. I got four of them for a christmas present two(?) years ago, two were covered in plastic, some sort of euro silver coins, and two bars, an englehard, and a new millenium, that were both uncovered.... The englehard tarnished (I think it did, maybe it came like that, it seemed to tarnish though over two years), the new millennium did not (the covered coins did not tarnish)..... The new millennium was a little rough in places, one edge was "sharp" to feel, and recently decided to just test it, spent 25 bucks, got a digital gram scale, and 5 vials of acid. weighed it, came out 10 percent heavier, tested it two places, on on the side equivocal. Another friend just gave me a silver coin 1964 half dollar (roughly 35 percent of an ounce of silver) a couple weeks ago. So my PM allocation is growing, representing 4.35 ounces of silver.

I am considering upping my precious metals investment at some point in time.
Last edited by LH on Mon Feb 04, 2013 10:53 pm, edited 2 times in total.
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Re: testing silver coins.... help

Post by LadyGeek »

This thread is now in the Personal Consumer Issues forum (coins).
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norookie
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Re: testing silver coins.... help

Post by norookie »

Hope my input helped! :happy
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WHL
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Re: testing silver coins.... help

Post by WHL »

Ive never tested any of mine. Do you have a strong magnet? If not, put the coins in your pocket and take a trip to the hardware store, find their magnets, and try it out. They should not stick, at all.

If all of that fails, find your local coin shop and ask them to test them.
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Re: testing silver coins.... help

Post by justus »

I've often been warned about buying fake silver bullion (rounds and bars), but you can usually feel the difference in both how it weighs and also the heat absorbency in your hands. Do you have other bars to compare it against?
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Re: testing silver coins.... help

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Re: testing silver coins.... help

Post by LH »

WHL wrote:Ive never tested any of mine. Do you have a strong magnet? If not, put the coins in your pocket and take a trip to the hardware store, find their magnets, and try it out. They should not stick, at all.

If all of that fails, find your local coin shop and ask them to test them.
yeah, have several neodymium magnets, it does appear to be para magnetic like silver, moving the magnet over it, there is some force felt with the motion, but the magnet does not move it or stick to it. (although if you wave the neodynium magnet rapidly over a coin, it does move it)
Last edited by LH on Mon Feb 04, 2013 11:02 pm, edited 1 time in total.
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LH
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Re: testing silver coins.... help

Post by LH »

justus wrote:I've often been warned about buying fake silver bullion (rounds and bars), but you can usually feel the difference in both how it weighs and also the heat absorbency in your hands. Do you have other bars to compare it against?
no not of the same brand.

It is exactly identical in appearance to the one list in the original link, that ones listed weight is ten percent less.
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Epsilon Delta
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Re: testing silver coins.... help

Post by Epsilon Delta »

Didn't Archimedes have something to say about this?
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Re: testing silver coins.... help

Post by Khanmots »

Surface tests are going to be of little use, I can't imagine that a fake wouldn't have been plated.

I'd be testing the density to see if it's got something else as a core. I'd suspect lead, but that'd only be 7-8% heavier...
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Re: testing silver coins.... help

Post by LH »

yeah, I should test density, haven't looked into it, you talking Archimedes water method? never understood how to functionally do that in reality, I understand the principle.

http://physics.weber.edu/carroll/archim ... nciple.htm

Image

Heh, I dunno how you get the water level such that its accurate, also my scale is not a suspension scale so cant do it that way easily that I can see....

I would have to weigh the dispaced water, but that again goes to accuracy in the displaced water. maybe its not as hard as I think accuracy wise.
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Re: testing silver coins.... help

Post by Joe S. »

LH wrote:
1)Just a priori, is it possible to have a one ounce silver coin that is real, yet weights 10 percent more????
Old US coins are 90% silver (so called junk silver), as pure silver is soft. However I would think a .999 pure ingot shouldn't be .900 pure. When I google the subject, I see no evidence of new millennium group ingots being .900 pure. However this "new millennium group" appears to be a scam (as pointed out by justus), so who knows what they put in their ingots.
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Re: testing silver coins.... help

Post by gatorman »

You might try this:

http://www.youtube.com/watch?v=89ATeNy3DIo

You'd need a micrometer or calipers and the ultrasonic thickness tester to do it. You might be able to find a bullion buyer who is properly equipped if you don't have access to the instruments or don't want to spend the money to buy the instruments. Rental might also be an option for the ultrasonic thickness tester. Calipers are inexpensive.

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Re: testing silver coins.... help

Post by Epsilon Delta »

LH wrote:yeah, I should test density, haven't looked into it, you talking Archimedes water method? never understood how to functionally do that in reality, I understand the principle.

Heh, I dunno how you get the water level such that its accurate, also my scale is not a suspension scale so cant do it that way easily that I can see....

I would have to weigh the dispaced water, but that again goes to accuracy in the displaced water. maybe its not as hard as I think accuracy wise.
For things the size of coins you can't measure the displaced water accurately. Surface tension will do you in, it is practically impossible to get the water level the same. You do need a suspension scale. Heres what you do:
1) Measure the bulk density of your water. If you have a liter of water you can measure the volume and weight to an accuracy of better than 0.1%.
2) Hang a basket from a mono-filament (fishing line) make a mark on the fishing line. Weigh the empty basket in air and immersed in your water up to the mark. Take care to remove any bubbles. The difference between the two weights is the buoyancy of your basket and string.
3) Put the coin in the basket and again weigh it in air and suspended up to the mark in water. The difference between these two weights is the buoyancy of the combined coin and basket.
4) Subtract the buoyancy of the basket to get the buoyancy of the coin.
5) Use the density of the water to calculate the volume of the coin.

The reason to use a mono-filament and a mark on it is to get the same amount of the string under water in both wet measurements. Because the mono-filament is so thin a difference of a few mm in the water level won't make much difference (.125mm * .125mm * 10mm) = 0.15mm^3 which gives an error of about .15mg.
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Re: testing silver coins.... help

Post by Dinero »

10% overweight is a big error, but this is on a private-mint bar. With privately minted stuff you just do not know what kind of quality control the manufacturer exercised. Maybe they deliberately cast slightly overweight bars to avoid returns of slightly underweight bars.

10% underweight on a circulated silver coin is certainly possible, though.

And silver is diamagnetic, not paramagnetic. My chemistry is rusty ( :happy ) , but in the presence of a strong magnetic field, diamagnetic materials resist a magnetic field while paramagnetic materials become slightly magnetic. Or so I recall. Probably too much inside baseball.
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Re: testing silver coins.... help

Post by carolinaman »

The Permanent Portfolio forum gets into discussion about precious metals. You may find your best answers there.
http://crawlingroad.com/blog/
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Re: testing silver coins.... help

Post by justus »

Joe S. wrote:
LH wrote:
1)Just a priori, is it possible to have a one ounce silver coin that is real, yet weights 10 percent more????
Old US coins are 90% silver (so called junk silver), as pure silver is soft. However I would think a .999 pure ingot shouldn't be .900 pure. When I google the subject, I see no evidence of new millennium group ingots being .900 pure. However this "new millennium group" appears to be a scam (as pointed out by justus), so who knows what they put in their ingots.
This is what I was trying to call out in the referenced blog post -- that the new millennium group's products may be fake and the owner/principal of the group Mr. Richard J.. Dompier has been convicted of passing off fake silver ingots. You generally don't have to compare 1 oz silver rounds or bars with others from the same foundry, but simply with other silver that you own. If you're new to stacking silver, you should buy from reputable sources until you're comfortable enough with the products to spot a fake. Fortunately, silver bars are still relatively cheap, so even if it's fake, you've got a great story & and interesting hunk of metal.
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Re: testing silver coins.... help

Post by Abe »

Go here and watch the video: https://www.youtube.com/watch?v=jY0bbRx3K64
Magnets don't always work. If you don't have nitric acid, you can take the coins to a pawn shop or jewelry store and they can check it for you. After watching the video, you will know more about it.
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Re: testing silver coins.... help

Post by Dogs »

gatorman wrote:You might try this:

http://www.youtube.com/watch?v=89ATeNy3DIo

You'd need a micrometer or calipers and the ultrasonic thickness tester to do it. You might be able to find a bullion buyer who is properly equipped if you don't have access to the instruments or don't want to spend the money to buy the instruments. Rental might also be an option for the ultrasonic thickness tester. Calipers are inexpensive.

gatorman
This is absolutely the best way to properly test your silver (or gold, platinum or any other metal, for that matter). An cheap ultrasonic thickness gauge will run you around $100-$150.

It wouldn't be a good investment for OP to just test a single silver round, but I would recommend it to anyone planning on regularly buying off-brand silver bullion. If you stick to well-known government minted coins and single ounce bars and rounds from the major bullion players (Johnson Matthey, Englehard, etc), then I would say it is not necessary.
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Re: testing silver coins.... help

Post by Joe S. »

justus wrote:
Joe S. wrote:
LH wrote:
1)Just a priori, is it possible to have a one ounce silver coin that is real, yet weights 10 percent more????
Old US coins are 90% silver (so called junk silver), as pure silver is soft. However I would think a .999 pure ingot shouldn't be .900 pure. When I google the subject, I see no evidence of new millennium group ingots being .900 pure. However this "new millennium group" appears to be a scam (as pointed out by justus), so who knows what they put in their ingots.
This is what I was trying to call out in the referenced blog post -- that the new millennium group's products may be fake and the owner/principal of the group Mr. Richard J.. Dompier has been convicted of passing off fake silver ingots. You generally don't have to compare 1 oz silver rounds or bars with others from the same foundry, but simply with other silver that you own. If you're new to stacking silver, you should buy from reputable sources until you're comfortable enough with the products to spot a fake. Fortunately, silver bars are still relatively cheap, so even if it's fake, you've got a great story & and interesting hunk of metal.
The story is somewhat confusing. This Dompier guy was apparently selling real silver ingots (made by the Franklin mint) at inflated prices. What was illegal was the Ponzi scheme he was selling along with the silver ingots.
http://blog.oregonlive.com/breakingnews ... s_sen.html

It's hard to resell 1 ounce silver ingots, even if they are genuine. If you want to invest in silver you should buy larger ingots/bars. There's less of a markup between buying and reselling. (Not that I recommend buying silver at all.)
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Re: testing silver coins.... help

Post by Dogs »

Joe S. wrote:It's hard to resell 1 ounce silver ingots, even if they are genuine. If you want to invest in silver you should buy larger ingots/bars. There's less of a markup between buying and reselling. (Not that I recommend buying silver at all.)
How is it hard to resell 1 oz ingots?

Also, the lowest premium silver is junk silver (circulated silver US coins), not large bars.
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Joe S.
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Re: testing silver coins.... help

Post by Joe S. »

Dogs wrote:
Joe S. wrote:It's hard to resell 1 ounce silver ingots, even if they are genuine. If you want to invest in silver you should buy larger ingots/bars. There's less of a markup between buying and reselling. (Not that I recommend buying silver at all.)
How is it hard to resell 1 oz ingots?
It is hard to resell 1 ounce silver ingots and make a decent profit due to the large markup between what you buy them for and what you sell them for.

I am unfamiliar with junk silver prices and spread.
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Re: testing silver coins.... help

Post by Dogs »

Joe S. wrote:It is hard to resell 1 ounce silver ingots and make a decent profit due to the large markup between what you buy them for and what you sell them for.

I am unfamiliar with junk silver prices and spread.
Larger ingots are no more profitable to resell than 1oz coins.
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