@ifthevamzarockin said:
I am sitting here with my 1oz Proof Gold Eagle some distilled water and some string. I am just not smart enough to figure out all this stuff. I think I will send it to PCGS and have them soak it in water for me.
@astrorat said:
Did you measure the coin's specific gravity?
Edited to add ... and measure the diameter and thickness?
When I began to research the specific gravity of an American Gold Eagle, I realized I had to determine what the theoretical specific gravity of the coin should be first prior to testing the one I have in hand.
So I took a look at the pamphlet included with the proof coin, and found that the Mint conveniently stated the exact composition of the coin's alloy in grams rather than percentages:
According to the pamphlet from the U.S. Mint, this coin should contain:
31.1 grams of pure Gold
Approximately 1.02 grams of pure Silver
Appoximately 1.81 grams of pure Copper
I decided to round after the 2nd decimal, given that the accuracy of my scale does not exceed +/- 0.01 grams anyway. This makes the math for calculating the theoretical specific gravity easier as it would be a foolhardy endeavor to compute the volume of space that each constituent component should occupy, but that will come later.
You will note that this cumulative composition adds up to 33.93 grams, rather than the stated mass of 33.931 grams the coin should be, according to the U.S. Mint pamphlet included with the coin. That is 99.997% of the theoretical mass of the coin, which is of acceptable accuracy for our purposes.
Now, to compute the volume of space each constituent component should occupy:
Gold has a specific gravity of 19.3 grams per cubic centimeter.
Silver has a specific gravity of 10.5 grams per cubic centimeter (rounded up from 10.49).
Copper has a specific gravity of 8.96 grams per cubic centimeter, though this metal has a varying SG based on the scientific source you quote.
That means the Gold in the coin should occupy a total volume of space of 31.1/19.3 = 1.611 cubic centimeters of Gold.
The Silver should occupy 0.1 cubic centimeters of space, based on 1.02/10.5 = 0.0.97 CC's (again, rounding by 2nd decimal).
The Copper should occupy 0.20 cubic centimeters of space, based on 1.81/8.96 = 0.202 CC's.
Which means the theoretical volume of the coin should be approximately 1.61+0.1+0.20 = 1.91 cubic centimeters of space. Based on our respectively derived calculation of the sum of the components' masses at 33.93 grams, that means the 1oz American Gold Eagle coin here should have a theoretical specific gravity of 33.93/1.91 = 17.76 g/cc. How patriotic! Maybe the mint planned this deliberately? Then again my math is the result of rounding by the 2nd decimal, the precise math could vary. But onwards. . .
Distilled water has an exact specific gravity of 1 gram per cubic centimeter. The theory behind water submersion/specific gravity tests is that, if you were submerge a coin in water (WITHOUT LETTING IT TOUCH THE BOTTOM OF THE CONTAINER - IT MUST BE SUSPENDED IN THE WATER FOR THE TEST TO BE ACCURATE; IT MUST ALSO NOT BE SUSPENDED BY ANY OBJECT THAT OCCUPIES A VOLUME OF SPACE WHICH EXCEEDS THE TOLERANCES FOR ERROR) that it would displace exactly one cubic centimeter of space of water for every cubic centimeter of space of coin which is submerged (and suspended) within it, which would consequently add one gram of weight to the scale for every cubic centimeter of water displaced. This assumes, as stated before, that the water is distilled and that the coin does not touch the bottom of the water container. To suspend the coin in the water without adding more volume to the scale is the tricky part. That's why a margin of error is necessary, because unless there's some massless/volumeless object which could hold the coin (magnetic suspension, perhaps? Then again, that might interfere with the scale), the strings or whatever you use to hold the coin will displace water as well. That's why it's important to use as little as possible material while suspending the coin. Anything else present in the water will interfere with the accuracy of the test.
But this is where a slight problem in the theory behind the tests' accuracy arises. Three small issues, really:
1) In practicality, when you submerge any object in water, microscopic bubbles on the bottom or side of the object (for a concave coin, or the reeds, or any high-relief coin, this issue would be particularly pronounced), the coin would have to be spritzed with distilled water first before submersion to minimize microscopic bubbles from adding to the perceived volume of the coin the bubbles' presence would create.
2) The volume of this coin is only theoretical and based on specific gravity for alloys by other scientific labs which may vary slightly, just enough, from one composition to another, based on who made it and under what circumstance, to where the actual specific gravity may be different.
3) When you calculate the theoretical volume by taking the constituent components' mass and working in reverse from their respective specific gravity, this will vary wildly from the mathematically-derived volume of a coin when based on a simple 3D model equation taken from a perfect cylinder.
Take the volumetric equation for a cylinder, V = pi (radius squared) * (height). That would be 3.14 times (half the diameter of a Gold Eagle (32.70mm), according to this U.S. Mint pamphlet, is 16.35mm or 1.64 centimeters (rounding to the 2nd decimal), to keep our units consistent with cubic centimeters), times the height (the stated thickness is 2.88mm, or 0.29 cm, rounding the 2nd decimal.
That would be 3.14 (1.64^2) (0.29) = 2.45 cubic centimeters of volume that a solid cylinder of equal stated dimensions that a Gold Eagle should be composed of should occupy if it had no relief, curved surfaces, concavity, or negative space in the reeding.
That gives us the absolute maximum amount of error possible in practice when actually submerging a coin in distilled water for volume calculation, as it is in this "negative space" (the difference between the SG-calculated volume, and the 3D perfect-cylinder calculated model). In other words, if you submerged a 1oz Gold Eagle in distilled water, and got a water displacement figure of lower than 1.91 CC's of space, or higher than 2.45 CC's of space, then you have either performed the test incorrectly (using incorrect water composition can cause variation, as can inaccurate scale, or using an implement that occupies too much space to suspend the coin in the water, can all cause the number to go up or down respectively) - or you have a fake coin which occupies too much or not enough volume of space. Either one is possible in this case. If this happens to you, recalibrate and carefully inspect your equipment, and if you keep getting bad results bring the coin to an expert for verification.
So now that we have our mathematical estimates, and know our anticipated range for upper and lower limits, I shall proceed to conduct the test on my coin. I will update you all once I have conducted it.
I love it when simple things are made complicated by over-thinking.
FACT: Unless you have the perfect set-up - controlled temp, closed and vibration-free balance accurate to +/- .00001 or more, platinum suspension wire as thin as three hairs, and then clean the object and remove any bubbles MOST OF WHICH you will not be able to see, etc., etc, etc. and then run the test at least three times in your "Clean Room," you won't have a chance of coming up with anything but a very good approximation. The smaller and lighter the coin, the harder it is. Try taking a worthwhile SG of a California fractional 25c. LOL.
That said, if you are very careful and have some of the above, you can weed out some fakes but the usual result is this. You can take the SG of a dozen .999 fine Gold Bullion pieces or a dozen .917 fine Saints and the results will be different than the posted scientific data or that from the mint. Nevertheless, you will be able to tell an object is not gold plated. All this in a shorter time than it took to read the post I just quoted.
PS I rarely run a time-consuming SG test anymore (except on rare occasions) because for several decades any really deceptive C/F virtually always will pass an SG. However, I had to do almost thirty SG's on Russian medals last week because I could tell a few were plated using a scope alone. Because of "the bad company in the group, the SG test caught about a half dozen more altered pieces.
Actually, thank you for mentioning platinum suspension wire for the SG test. I just realized another way to narrow the margin of error for the test:
Assuming we are using platinum wire (or any other substance which would not absorb the water, or lose any volume, when submerged), one can simply submerge the suspension device first, without any coin on it, at a predetermined fixed-height and tare the scale with the device submerged that precise level. That way, when you do suspend the coin to perform the actual test, the volume displaced by the suspension apparatus (in this case, razor-thin platinum suspension strings) would not interfere with the tested results. (Assuming you submerge the same exact consistent amount of platinum wire, or whatever material your suspension apparatus is composed of).
Thanks for making me think of that. It's always good to think of ways to minimize error.
Did you confirm that .288 cm is the planchet thickness or more likely the coin thickness measured at the rim after striking? I recommend you get a micrometer and check these two numbers to be sure.
_
I have not confirmed it yet. I want to be as careful as possible when I use my calipers, and want to devise a way to hold the coin steady without touching it. Maybe a vise with felt on each face, or cotton made of the same kind designed to handle coins with. Either should be safe, though I will test the setup first on a cheaper coin first to see if there's anything I should anticipate.
Also, mathematically you should never round to 2 places before multiplying. You should use the full Mint and more significant digits on pi information and then round if you choose to. So 3.1416 * 1.635^2*.288 or 2.4187 or 2.42cc which is a better compare than 2.45. However, the fact that you calculated 1.91cc to be the more correct mathematical volume, the 2.42 figure proves to me the Mint thickness is overstated and is the rim thickness after minting, and so this cross check is irrelevant._
Rounding to a later digit and using the final two digits would be useful for my scale. I just figured the difference in results would be minuscule, which 0.03 cc's is.
As for rim thickness, I don't believe the Mint overstated it. As I noted in my earlier post, that calculation assumes the coin is a perfect cylinder - it isn't. It has reeds, recessed faces on both sides, the intricacies of the negative space of the devices on the relief, etc. The only way to accurately calculate the volume based on measurements outside of the metallic composition would be to resort to calculus, which is beyond my expertise.
If you can actually measure volume to the nearest 1/100 of a cc, just compare your result to the 1.91cc you calculated and see the variance._
That's my plan. The point of the 2.45 (or as you calculate, 2.42) cc figure is to see how much in microscopic air bubbles could possibly throw off the results. Hence the intrinsic value and necessity in calculating that as well.
But seriously, is this really worth the trouble to get another questionable result? The proof eagle pictured is genuine.
_
There was a machinist in Oregon (or California, I'm not sure anymore) who cleverly bought several authentic Gold coins, cut them in half, milled out the gold in the middle, and placed tungsten slugs in the center and sold them to unsuspecting pawn shops in the local area. They were cheated out of $50K or $100K before he was caught.
I wouldn't ever want to be a victim of a scam like that. People can take real coins, such as one like in the photos I took above would show the face and reverse of an authentic coin (as they appear to be), and simply hollow out the core to be fraudulently altered and swapped with fake metal.
When the day comes that every coin shop has technology to view inside a coin for slugs (and to compare that test with XRF analysis on the surface level), both I and many collectors (and investors) will have their hearts put at ease. This would ultimately benefit us all, as I know many millionaires (business owners, real estate investors, etc) who thought about bullion or rare-coin investing but ultimately decided to walk away from it because of the high-risk of fakes (and their perpetually-advancing state and quality). If those fears could be alleviated, those of us who have invested in coins could see our investments rise significantly in value.
Companies like Sigma Metalytics are doing a service to the public, as far as I'm concerned. A wonderful little device that improves dramatically (though not perfectly, but certainly better than without it) the ability to detect fakes. Mine has saved me before, for sure.
That said, I must say that I am deeply disappointed in the XRF companies. No one seems to make a reliable XRF for precious metals that isn't $10K-$30K+. That's absurd, and the sooner the prices come down dramatically so that anti-counterfeiting technology can disseminate, the better for us all.
Ultrasonic thickness testing is another useful avenue for precious metals verification. Those are already incredibly cheap. For $50 or less on eBay you can get one designed to measure several inches thick of metals, which is very good for 10oz and 100oz Silver bars. The only problem with the nature of that technology is that you have to use glycerin to mate the inductor with the metal. Otherwise it can't measure it. So it's really only good for bullion given the physical contact, not proof or rare coins. But, better than nothing.
I could go on, but I think you get my point. As time goes on, fakes will continue to improve, and my cautious nature will increase in direct correlation with that.
@ifthevamzarockin said:
I am sitting here with my 1oz Proof Gold Eagle some distilled water and some string. I am just not smart enough to figure out all this stuff. I think I will send it to PCGS and have them soak it in water for me.
String or thread is a no.no.
How bout if I Super Glue a hair to it?
Nope. However, I have used a strand of long black hair from an Italian woman for over twenty years BEFORE I switched to the platinum wire.
Redstone,
You are welcome and I cannot wait to see the fancy apparatus it appears you are going to devise with the wire. I'll share some more tips with you soon. For now, a search of the Internet should provide the ideal temperature for the distilled water you use. Additionally, you'll need to find the formula to account for the effects of SURFACE TENSION in your calculations.
@Goldminers said:
Why not buy just them direct from the Mint? They will cost more but they are probably real and you would not have to go through all this stress.
There are over 600,000 packages stolen every year by USPS employees, and millions more by front-door package thieves.
There have even been, historically documented in public record, U.S. Mint employees who stole gold and coins from the Mint.
I wouldn't put it past a criminal at any point in the supply chain to put a well-made fake in the box, or to swap out a real one for a fake one, especially since they would likely believe that most people would never test their Gold.
As time goes on, and counterfeiting technology gets more advanced, it will become increasingly irrelevant who you buy from. It will begin to matter who shipped it, and who handled it in the interim, which will determine the probability of someone in the supply chain pulling a bait-and-switch on an unsuspecting buyer. And crooks especially know that most buyers would never suspect a coin bought directly from the government, or any one of those highly-reputable dealers, to contain a fake coin. Hence why they are, along with their customers, the biggest targets of all.
I am not stressed at all about fakes. My knowledge of their mass diffusion was initially frustrating for me, but as I've learned to verify even older, pre-Chinese-mass-counterfeiting-era coins from decades ago (like the infamous Lebanese fake $2.5 and $5 gold Indians, or old fake $1 gold coins, etc), I've realized that verification is a necessity no matter who you buy from.
Once I was sold fake Morgan Dollars by a brick-and-mortar shop nearby, I realized even dealers were being fooled. Well, I refuse to be fooled. I will always verify my coins, no matter the source.
The sooner everyone else verifies their own coins, the better. Too many fakes and money on the line to risk it.
I just edited my post and it did not delete. Maybe you are being hacked by someone or need to update something. Better scan for a virus and reboot your computer or phone. One can't be too careful.
I find it extremely hard to believe that you are not "stressed-out" over-the-top by counterfeit coins in spite of this statement:
"I am not stressed at all about fakes. My knowledge of their mass diffusion was initially frustrating for me, but as I've learned to verify even older, pre-Chinese-mass-counterfeiting-era coins from decades ago (like the infamous Lebanese fake $2.5 and $5 gold Indians, or old fake $1 gold coins, etc), I've realized that verification is a necessity no matter who you buy from."
There is no way to reply to the "LESS THAN infamous" crap made in Lebanon in the 1960's and 70's without being a "showoff" as I was called. Nevertheless, as a 27-year-old "new hire," within the first fifteen minutes at the microscope, I learned that there was not one deceptive "ANYTHING" being made in Lebanon. Every fake became an across-the-room, naked-eye, wrong-color, mushy imitation that was not even close to appearing genuine! Those die-struck lumps of crap from Lebanon were so crude that a top authentication expert (in his own mind) was telling folks they were cast counterfeits! That junk still fooled dealers and collectors and kept the money pouring into the authentication service. It was not until the late 1970's that the product improved enough that a microscope was needed again.
So you see, this statement of yours below is not going to happen - EVER!
Realcoin had a nice thought: "The sooner everyone else verifies their own coins, the better. Too many fakes and money on the line to risk it."
We are lucky to have the TPGS performing this service. That way, when folks go around questioning the authenticity of coins, they have a place to turn.
@RedstoneCoins said:
Yet again, my reply was deleted by PCGS when I opened it to edit a grammatical error.
What is going on with this website?
It’s both you and the forum software.
Making multiple edits in short period of time may cause the software to think your trying to do something you shouldn’t, i.e., cause an error and crash the system. It’s especially active for new users.
Recommend you make a copy of your post (just save it to buffer) prior to hitting the post/save button. In this way, if it gets wacked, you can make a new post and paste.
@Goldminers said:
I just edited my post and it did not delete. Maybe you are being hacked by someone or need to update something. Better scan for a virus and reboot your computer or phone. One can't be too careful.
I just checked my computer for a virus.
It told me my computer weighed the wrong amount, and that was causing the issue.
Disbelieving the software, I submerged my computer in water to check its' specific gravity.
The good news is it came up as the correct volume. The bad news is that now my computer is fried.
The most clever virus I have ever encountered! Got me to soak my computer in water.
@Goldminers said:
I just edited my post and it did not delete. Maybe you are being hacked by someone or need to update something. Better scan for a virus and reboot your computer or phone. One can't be too careful.
I just checked my computer for a virus.
It told me my computer weighed the wrong amount, and that was causing the issue.
Disbelieving the software, I submerged my computer in water to check its' specific gravity.
The good news is it came up as the correct volume. The bad news is that now my computer is now fried.
The most clever virus I have ever encountered! Got me to soak my computer in water.
According to the pamphlet from the U.S. Mint, this coin should contain:
31.1 grams of pure Gold
Approximately 1.02 grams of pure Silver
Appoximately 1.81 grams of pure Copper
31.1g of gold is a minimum. You also need to know the standard deviation (SD) and/or confidence interval (CI). Say it is the typical 95% normally distributed, what this means is that 97.5% of the time there will be 31.1g or more of gold and 2.5% of the time there will be less than 31.1g.
If you absolutely can't have less than 31.1g then you need to weight each planchet and discard the lightweight ones.
Let us say that our standard deviation (SD) is 0.005g - reasonable given several of the measurements are given to two decimal places.
1.96SD is the 95% CI, meaning that our low value is 31.1 - 0.0098 or 31.0902g for the gold and our high value is 31.1098
Silver is 1.02 +/- 0.0098 or 1.0102 - 1.0298
Copper is 1.81 +/- 0.0098 or 1.8002 - 1.8198
Thus the total is between (31.0902 + 1.0102 + 1.8002) and (31.1098 + 1.0298 + 1.8198) or between 33.9006g and 33.9594g
-----Burton ANA 50 year/Life Member (now "Emeritus")
My eyes are glazing over reading all of this, but it is interesting to hear the theory behind it when I see gravity result and stuff mentioned in other threads.
I’m going to stick with collecting parking lot Lincoln’s so I won’t have to worry.
Collector of randomness. Photographer at PCGS. Lover of Harry Potter.
If you absolutely can't have less than 31.1g then you need to weight each planchet and discard the lightweight ones.
Interesting discussion, just a comment on the quote above. Its entirely possible, I would even say likely that the do weigh each planchet and remelt each one that is low. That is a common manufacturing technique.
@SiriusBlack said:
My eyes are glazing over reading all of this, but it is interesting to hear the theory behind it when I see gravity result and stuff mentioned in other threads.
I’m going to stick with collecting parking lot Lincoln’s so I won’t have to worry.
You better make sure those "ground treasures" you find are genuine!
Assuming it is genuine you got about .2 grams of extra mostly gold, so at $1,505/ounce is almost $10 extra value!
Consider the silver lining, not the dark clouds.
Of the many Gold coins I have bought from various mints, especially of the old $20 Gold Double Eagles, I have never gotten overweight coins. Usually from wear I'm lucky if they're at spec, which for an old $20 piece is about 33.4 grams.
Just seems very odd to me that twice in a row the coins from this particular seller are overweight, but then again I've never handled Proof Gold Eagles, so it is a new frontier for me.
I came here to ask for help. I figured other people on this board would have Proof Gold Eagles they might have the ability to weigh for comparison. That would be helpful. Hence my post.
@Goldminers said:
Assuming it is genuine you got about .2 grams of extra mostly gold, so at $1,505/ounce is almost $10 extra value!
Consider the silver lining, not the dark clouds.
I sure hope it's extra Gold and not something else.
My specific gravity test will help verify that. I'm in the process of acquiring a new suspension setup right now. Hopefully when it's done I can post accurate results of the volume of each coin, the 34.08 and the 34.14, respectively.
@Goldminers said:
Assuming it is genuine you got about .2 grams of extra mostly gold, so at $1,505/ounce is almost $10 extra value!
Consider the silver lining, not the dark clouds.
I sure hope it's extra Gold and not something else.
My specific gravity test will help verify that. I'm in the process of acquiring a new suspension setup right now. Hopefully when it's done I can post accurate results of the volume of each coin, the 34.08 and the 34.14, respectively.
Any coin, like a proof, that has a premium over gold weight could be made of real gold and still be profitable to the counterfeiter...if you really want to be extra paranoid.
@Goldminers said:
Assuming it is genuine you got about .2 grams of extra mostly gold, so at $1,505/ounce is almost $10 extra value!
Consider the silver lining, not the dark clouds.
I sure hope it's extra Gold and NOT something else.
My specific gravity test will help verify that. I'm in the process of acquiring a new suspension setup right now. Hopefully when it's done I can post accurate results of the volume of each coin, the 34.08 and the 34.14, respectively.
Can you check to make sure it is not one of those Tungsten counterfeits with a very thick gold plating?
Title of this thread should be "Not close enough for government work."> @RedstoneCoins said:
I figured other people on this board would have Proof Gold Eagles they might have the ability to weigh for comparison. That would be helpful. Hence my post.
Once I was sold fake Morgan Dollars by a brick-and-mortar shop nearby, I realized even dealers were being fooled. Well, I refuse to be fooled. I will always verify my coins, no matter the source.
That's generous of you. Many would assume the dealer was trying to rip you off. If I buy a deal of coins and have some fake Morgans thrown in, I'd destroy the phony Morgans, but not everyone would.
@Goldminers said:
So far all of mine weigh between 61-63 grams, but they have about 28 grams of clear plastic and little paper labels stuck in them.
Well crack 'em out and reweigh them. Are you trying to be helpful or not?
You should also scratch the edge and make sure there isn't copper underneath.
I considered dissolving them in Aqua Regia to see how much the SG increases, but I'm a little low on nitric and HCL acid to make it. PCGS also said it would void the guarantee
What year is your coin, if I might ask? I'm sure the quality and consistency of the Mints' planchets have varied over time based on mint director and staff.
Other Gold Eagles I bought a while back (not Proofs) weighed 33.98 and 33.99 grams. Those didn't come over eBay, so my concern over them was significantly less despite their slight excess weight over spec.
Practically every generic/non-government round I've ever bought was exactly 31.1 grams, when .999 fine. It's kind of perplexing to me that the private industries, in my experience, seem to have tighter quality control than the government (from what I've handled). Most Silver Eagles I've bought weighed 31.2 all the way up to 31.4 grams.
Then again generic bullion can never be legal tender, so there is that advantage to Gold Eagles/Silver Eagles.
I appreciate your data input. Glad to get some correlation with other coins from another source.
Comments
How bout if I Super Glue a hair to it?
Don't forget, it already passed the picture test.
Exit bunker, enter Matrix. LOL
Actually, thank you for mentioning platinum suspension wire for the SG test. I just realized another way to narrow the margin of error for the test:
Assuming we are using platinum wire (or any other substance which would not absorb the water, or lose any volume, when submerged), one can simply submerge the suspension device first, without any coin on it, at a predetermined fixed-height and tare the scale with the device submerged that precise level. That way, when you do suspend the coin to perform the actual test, the volume displaced by the suspension apparatus (in this case, razor-thin platinum suspension strings) would not interfere with the tested results. (Assuming you submerge the same exact consistent amount of platinum wire, or whatever material your suspension apparatus is composed of).
Thanks for making me think of that. It's always good to think of ways to minimize error.
_> @Goldminers said:
Yes, and that's the point. If the U.S government cannot make their products consistent and trustworthy, then that is an issue.
_> @Goldminers said:
_
I have not confirmed it yet. I want to be as careful as possible when I use my calipers, and want to devise a way to hold the coin steady without touching it. Maybe a vise with felt on each face, or cotton made of the same kind designed to handle coins with. Either should be safe, though I will test the setup first on a cheaper coin first to see if there's anything I should anticipate.
_> @Goldminers said:
Rounding to a later digit and using the final two digits would be useful for my scale. I just figured the difference in results would be minuscule, which 0.03 cc's is.
As for rim thickness, I don't believe the Mint overstated it. As I noted in my earlier post, that calculation assumes the coin is a perfect cylinder - it isn't. It has reeds, recessed faces on both sides, the intricacies of the negative space of the devices on the relief, etc. The only way to accurately calculate the volume based on measurements outside of the metallic composition would be to resort to calculus, which is beyond my expertise.
_> @Goldminers said:
That's my plan. The point of the 2.45 (or as you calculate, 2.42) cc figure is to see how much in microscopic air bubbles could possibly throw off the results. Hence the intrinsic value and necessity in calculating that as well.
_> @Goldminers said:
_
There was a machinist in Oregon (or California, I'm not sure anymore) who cleverly bought several authentic Gold coins, cut them in half, milled out the gold in the middle, and placed tungsten slugs in the center and sold them to unsuspecting pawn shops in the local area. They were cheated out of $50K or $100K before he was caught.
I wouldn't ever want to be a victim of a scam like that. People can take real coins, such as one like in the photos I took above would show the face and reverse of an authentic coin (as they appear to be), and simply hollow out the core to be fraudulently altered and swapped with fake metal.
When the day comes that every coin shop has technology to view inside a coin for slugs (and to compare that test with XRF analysis on the surface level), both I and many collectors (and investors) will have their hearts put at ease. This would ultimately benefit us all, as I know many millionaires (business owners, real estate investors, etc) who thought about bullion or rare-coin investing but ultimately decided to walk away from it because of the high-risk of fakes (and their perpetually-advancing state and quality). If those fears could be alleviated, those of us who have invested in coins could see our investments rise significantly in value.
Companies like Sigma Metalytics are doing a service to the public, as far as I'm concerned. A wonderful little device that improves dramatically (though not perfectly, but certainly better than without it) the ability to detect fakes. Mine has saved me before, for sure.
That said, I must say that I am deeply disappointed in the XRF companies. No one seems to make a reliable XRF for precious metals that isn't $10K-$30K+. That's absurd, and the sooner the prices come down dramatically so that anti-counterfeiting technology can disseminate, the better for us all.
Ultrasonic thickness testing is another useful avenue for precious metals verification. Those are already incredibly cheap. For $50 or less on eBay you can get one designed to measure several inches thick of metals, which is very good for 10oz and 100oz Silver bars. The only problem with the nature of that technology is that you have to use glycerin to mate the inductor with the metal. Otherwise it can't measure it. So it's really only good for bullion given the physical contact, not proof or rare coins. But, better than nothing.
I could go on, but I think you get my point. As time goes on, fakes will continue to improve, and my cautious nature will increase in direct correlation with that.
Thanks.
Why not buy just them direct from the Mint? They will cost more but they are probably real and you would not have to go through all this stress.
My US Mint Commemorative Medal Set
Nope. However, I have used a strand of long black hair from an Italian woman for over twenty years BEFORE I switched to the platinum wire.
Redstone,
You are welcome and I cannot wait to see the fancy apparatus it appears you are going to devise with the wire. I'll
share some more tips with you soon. For now, a search of the Internet should provide the ideal temperature for the distilled water you use. Additionally, you'll need to find the formula to account for the effects of SURFACE TENSION in your calculations.
Are you going to test the wire first to be sure it's platinum?
Agree, some shifty jewelers may cheat you on the fineness of the platinum. Worst-case scenario, bend a paper clip.
There are over 600,000 packages stolen every year by USPS employees, and millions more by front-door package thieves.
There have even been, historically documented in public record, U.S. Mint employees who stole gold and coins from the Mint.
I wouldn't put it past a criminal at any point in the supply chain to put a well-made fake in the box, or to swap out a real one for a fake one, especially since they would likely believe that most people would never test their Gold.
As time goes on, and counterfeiting technology gets more advanced, it will become increasingly irrelevant who you buy from. It will begin to matter who shipped it, and who handled it in the interim, which will determine the probability of someone in the supply chain pulling a bait-and-switch on an unsuspecting buyer. And crooks especially know that most buyers would never suspect a coin bought directly from the government, or any one of those highly-reputable dealers, to contain a fake coin. Hence why they are, along with their customers, the biggest targets of all.
I am not stressed at all about fakes. My knowledge of their mass diffusion was initially frustrating for me, but as I've learned to verify even older, pre-Chinese-mass-counterfeiting-era coins from decades ago (like the infamous Lebanese fake $2.5 and $5 gold Indians, or old fake $1 gold coins, etc), I've realized that verification is a necessity no matter who you buy from.
Once I was sold fake Morgan Dollars by a brick-and-mortar shop nearby, I realized even dealers were being fooled. Well, I refuse to be fooled. I will always verify my coins, no matter the source.
The sooner everyone else verifies their own coins, the better. Too many fakes and money on the line to risk it.
Yet again, my reply was deleted by PCGS when I opened it to edit a grammatical error.
What is going on with this website?
I just edited my post and it did not delete. Maybe you are being hacked by someone or need to update something. Better scan for a virus and reboot your computer or phone. One can't be too careful.
My US Mint Commemorative Medal Set
Redstone,
I find it extremely hard to believe that you are not "stressed-out" over-the-top by counterfeit coins in spite of this statement:
"I am not stressed at all about fakes. My knowledge of their mass diffusion was initially frustrating for me, but as I've learned to verify even older, pre-Chinese-mass-counterfeiting-era coins from decades ago (like the infamous Lebanese fake $2.5 and $5 gold Indians, or old fake $1 gold coins, etc), I've realized that verification is a necessity no matter who you buy from."
There is no way to reply to the "LESS THAN infamous" crap made in Lebanon in the 1960's and 70's without being a "showoff" as I was called. Nevertheless, as a 27-year-old "new hire," within the first fifteen minutes at the microscope, I learned that there was not one deceptive "ANYTHING" being made in Lebanon. Every fake became an across-the-room, naked-eye, wrong-color, mushy imitation that was not even close to appearing genuine! Those die-struck lumps of crap from Lebanon were so crude that a top authentication expert (in his own mind) was telling folks they were cast counterfeits! That junk still fooled dealers and collectors and kept the money pouring into the authentication service.
It was not until the late 1970's that the product improved enough that a microscope was needed again.
So you see, this statement of yours below is not going to happen - EVER!
Realcoin had a nice thought: "The sooner everyone else verifies their own coins, the better. Too many fakes and money on the line to risk it."
We are lucky to have the TPGS performing this service. That way, when folks go around questioning the authenticity of coins, they have a place to turn.
All of this is why I buy my "bullion" from China. At least I know up front what I am not getting.
It’s both you and the forum software.
Making multiple edits in short period of time may cause the software to think your trying to do something you shouldn’t, i.e., cause an error and crash the system. It’s especially active for new users.
Recommend you make a copy of your post (just save it to buffer) prior to hitting the post/save button. In this way, if it gets wacked, you can make a new post and paste.
I just checked my computer for a virus.
It told me my computer weighed the wrong amount, and that was causing the issue.
Disbelieving the software, I submerged my computer in water to check its' specific gravity.
The good news is it came up as the correct volume. The bad news is that now my computer is fried.
The most clever virus I have ever encountered! Got me to soak my computer in water.
China or anywhere in Asia.
Post of the day
Collector, occasional seller
Title of this thread should be "Not close enough for government work."
Exit bunker, enter Matrix. LOL
Better yet: "ANSWERED"
Nice idea but scientifically inaccurate. You are assuming the errors tend to the mean when adding and they don't have to.
Good starting point: https://reference.wolfram.com/applications/eda/ExperimentalErrorsAndErrorAnalysis.html
Also https://www.bmj.com/about-bmj/resources-readers/publications/statistics-square-one/4-statements-probability-and-confiden
31.1g of gold is a minimum. You also need to know the standard deviation (SD) and/or confidence interval (CI). Say it is the typical 95% normally distributed, what this means is that 97.5% of the time there will be 31.1g or more of gold and 2.5% of the time there will be less than 31.1g.
If you absolutely can't have less than 31.1g then you need to weight each planchet and discard the lightweight ones.
Let us say that our standard deviation (SD) is 0.005g - reasonable given several of the measurements are given to two decimal places.
1.96SD is the 95% CI, meaning that our low value is 31.1 - 0.0098 or 31.0902g for the gold and our high value is 31.1098
Silver is 1.02 +/- 0.0098 or 1.0102 - 1.0298
Copper is 1.81 +/- 0.0098 or 1.8002 - 1.8198
Thus the total is between (31.0902 + 1.0102 + 1.8002) and (31.1098 + 1.0298 + 1.8198) or between 33.9006g and 33.9594g
ANA 50 year/Life Member (now "Emeritus")
You and the OP are very informative!
My eyes are glazing over reading all of this, but it is interesting to hear the theory behind it when I see gravity result and stuff mentioned in other threads.
I’m going to stick with collecting parking lot Lincoln’s so I won’t have to worry.
Collector of randomness. Photographer at PCGS. Lover of Harry Potter.
Interesting discussion, just a comment on the quote above. Its entirely possible, I would even say likely that the do weigh each planchet and remelt each one that is low. That is a common manufacturing technique.
You better make sure those "ground treasures" you find are genuine!
Help needed again, everyone.
Second coin Seller sent weighs 34.14 grams.
Passes the Sigma Metalytics test, details look right. I have not inspected the rims under the microscope yet for machining or mating.
Is this just more of the same U.S. government unreliability, or is this a fake/altered coin?
I just wish the damn thing would weigh 33.93 grams so I could rest easy.
For math reference, this is 100.62% of spec weight.
His scale might need to be calibrated. Can't really trust him/ her weighting another one of a genuine 1 oz eagle in their possession.
You have to be kidding.
You do realize that 33.93 is the minimum, not the exact weight- right?
Assuming it is genuine you got about .2 grams of extra mostly gold, so at $1,505/ounce is almost $10 extra value!
Consider the silver lining, not the dark clouds.
My US Mint Commemorative Medal Set
Hey, you should send your findings to the Director of the Mint. They need to be alerted of what's going on. -
Of the many Gold coins I have bought from various mints, especially of the old $20 Gold Double Eagles, I have never gotten overweight coins. Usually from wear I'm lucky if they're at spec, which for an old $20 piece is about 33.4 grams.
Just seems very odd to me that twice in a row the coins from this particular seller are overweight, but then again I've never handled Proof Gold Eagles, so it is a new frontier for me.
I came here to ask for help. I figured other people on this board would have Proof Gold Eagles they might have the ability to weigh for comparison. That would be helpful. Hence my post.
I sure hope it's extra Gold and not something else.
My specific gravity test will help verify that. I'm in the process of acquiring a new suspension setup right now. Hopefully when it's done I can post accurate results of the volume of each coin, the 34.08 and the 34.14, respectively.
Any coin, like a proof, that has a premium over gold weight could be made of real gold and still be profitable to the counterfeiter...if you really want to be extra paranoid.
Weighed one just now- 34.08g
Can you check to make sure it is not one of those Tungsten counterfeits with a very thick gold plating?
You've got a fake, also?!?!?!?
Only if the mint mailed out fakes. I'm not holding my breath waiting to confirm that.
Title of this thread should be "Not close enough for government work."> @RedstoneCoins said:
Irrelevant unless the same scale is used.
Exit bunker, enter Matrix. LOL
So far all of mine weigh between 61-63 grams, but they have about 28 grams of clear plastic and little paper labels stuck in them.
My US Mint Commemorative Medal Set
Well crack 'em out and reweigh them. Are you trying to be helpful or not?
You should also scratch the edge and make sure there isn't copper underneath.
That's generous of you. Many would assume the dealer was trying to rip you off. If I buy a deal of coins and have some fake Morgans thrown in, I'd destroy the phony Morgans, but not everyone would.
I considered dissolving them in Aqua Regia to see how much the SG increases, but I'm a little low on nitric and HCL acid to make it. PCGS also said it would void the guarantee
My US Mint Commemorative Medal Set
Thank you.
What year is your coin, if I might ask? I'm sure the quality and consistency of the Mints' planchets have varied over time based on mint director and staff.
Other Gold Eagles I bought a while back (not Proofs) weighed 33.98 and 33.99 grams. Those didn't come over eBay, so my concern over them was significantly less despite their slight excess weight over spec.
Practically every generic/non-government round I've ever bought was exactly 31.1 grams, when .999 fine. It's kind of perplexing to me that the private industries, in my experience, seem to have tighter quality control than the government (from what I've handled). Most Silver Eagles I've bought weighed 31.2 all the way up to 31.4 grams.
Then again generic bullion can never be legal tender, so there is that advantage to Gold Eagles/Silver Eagles.
I appreciate your data input. Glad to get some correlation with other coins from another source.