Fake or Underweight Gold Britannias?

[perky416]

Hi Guys,

New here but not new to the precious metal scene. Im after some advice with regards to some coins I purchased, as I dont know anybody else that invests and this being a well established forum I couldn't think of a better place to go .

A while back I purchased some 2015 Gold Britannias, recently when moving storage locations I decided to have a look at them and I noticed that one of the tubes of 10 was about half a coin shorter than the others when stacked next to each other. I got in touch with the Royal Mint who advised that dimensions can vary slightly but as long as they all weight over 32.21g they are fine.

When weighing them (on the myweigh 250 scales) I found 2 of the coins to be fairly underweight coming in at 31.14g & 31.15g.

The Royal Mint told me to return them to the retailer so they could raise an investigation however as I purchased them over 2 years ago they dont want to know, they wont even get back to me (absolutely terrible customer service).

I am in the process of testing these coins to find out of they are simply underweight or fakes.

So my question to you guys is have you ever come across fake or underweight Gold Britannias? I am trying to get a feel for how normal this situation is.

Many Thanks

[Kman]

Where did you buy them from? 

[sixgun]

Put some high quality photos of the coins up.

How do you know your scale is correct?

[sovereignsteve]

Are all the others the correct weight? Over a gram shy is a lot and far too much to be genuine.

[silversky]

Hi Perky,

If your brits are 2015 then they should be .9999 fineness.  That means they should weigh almost exactly one troy ounce.  One troy ounce is 31.1035g and not the 32.21g you mentioned from the mint.  It's also less than the 31.15g that you say yours are weighing.  Perhaps your scales need calibrating.  I've seen somewhere a description that says a Britannia can weigh up to 31.2g (I think this is just rounding up on less accurate scales tbh) which would be only a tiny 0.0965g more than the 31.1035g that is a troy ounce.  The figure you said that the royal mint gave you cannot possibly be the case for a new 999 Britannia.  They just simply wouldn't be giving out an extra 1g (£30) of free gold with every coin.  Perhaps the figure quoted by them was for an older coin that is not of 999 fineness?

Anyway, you should measure them with digital callipers (pretty cheap to buy) and check against the official measurements on the mints page for the 2015 Britannia.  My Britannia is pretty much spot on and came from a very reputable bullion dealer so you should expect yours be very close to the correct weight.  If the weight is correct then most fakes are much larger than the official dimensions to enable the weight to be correct.  If the size is correct then the weight will likely be underweight if it is a fake.  This is not definitely true though as it's potentially possible to make a plated platter that ends up being the correct weight and dimension albeit very very difficult.  You could always make up a magnetic slide from N42 neodymium magnets that you can buy in flat form and glue to a piece of wood in a series 6 inches long.  Then place at about 60-70deg angle and compare the speed of the different brit coins you have running down it.  They should all run at the same speed for the same metal so it would show you if there is any difference.  A multi metal platter will not run down a neodymium slide at the same speed as a pure gold one does as it's overall conductivity is different.

What size are the two suspect coins relative to the other coins?  Did they all come in the same tubes or were they bought at different times and from different dealers?

Finally, who did you buy them from if you don't mind me asking?

Cheers

Edited January 28, 2017 by silversky

[perky416]

Hi Guys thanks for the replys. Please see my response to each of you below.

22 hours ago, Kman said:

Where did you buy them from? 

I go them from thegoldbullion.co.uk which is based in Birminghams Jewellery Quarter, I think they also operate under Jewellery Quarter Bullion Ltd and Sabre Jewellery Limited.

17 hours ago, sixgun said:

Put some high quality photos of the coins up.

How do you know your scale is correct?

I have attached a couple of pics of a coin from the suspect batch along with the original pic where I identified the height as being different. I took a lot of measurements of my coins which you can see in the table attached in response to silversky below, as you can see I took 5 readings of each coin from 2 batches and they are very consistent, I also calibrated the scales every 5 coins. The scuffs on the queens face are where the coins have been rubbing but please take note of the faded "100 POUNDS", this is the same on all coins in that batch.

17 hours ago, sovereignsteve said:

Are all the others the correct weight? Over a gram shy is a lot and far too much to be genuine.

The majority of the coins weigh the same, please see the table of my weights below. Sorry I think you may have miss-read, its not over a gram shy at worst it is 0.07g from what the mint quoted me.

12 hours ago, silversky said:

Hi Perky,

If your brits are 2015 then they should be .9999 fineness.  That means they should weigh almost exactly one troy ounce.  One troy ounce is 31.1035g and not the 32.21g you mentioned from the mint.  It's also less than the 31.15g that you say yours are weighing.  Perhaps your scales need calibrating.  I've seen somewhere a description that says a Britannia can weigh up to 31.2g (I think this is just rounding up on less accurate scales tbh) which would be only a tiny 0.0965g more than the 31.1035g that is a troy ounce.  The figure you said that the royal mint gave you cannot possibly be the case for a new 999 Britannia.  They just simply wouldn't be giving out an extra 1g (£30) of free gold with every coin.  Perhaps the figure quoted by them was for an older coin that is not of 999 fineness?

Anyway, you should measure them with digital callipers (pretty cheap to buy) and check against the official measurements on the mints page for the 2015 Britannia.  My Britannia is pretty much spot on and came from a very reputable bullion dealer so you should expect yours be very close to the correct weight.  If the weight is correct then most fakes are much larger than the official dimensions to enable the weight to be correct.  If the size is correct then the weight will likely be underweight if it is a fake.  This is not definitely true though as it's potentially possible to make a plated platter that ends up being the correct weight and dimension albeit very very difficult.  You could always make up a magnetic slide from N42 neodymium magnets that you can buy in flat form and glue to a piece of wood in a series 6 inches long.  Then place at about 60-70deg angle and compare the speed of the different brit coins you have running down it.  They should all run at the same speed for the same metal so it would show you if there is any difference.  A multi metal platter will not run down a neodymium slide at the same speed as a pure gold one does as it's overall conductivity is different.

What size are the two suspect coins relative to the other coins?  Did they all come in the same tubes or were they bought at different times and from different dealers?

Finally, who did you buy them from if you don't mind me asking?

Cheers

Please see the attachments for a print screen of the initial reply I got from the Royal Mint, this was in response to me telling them I had 2015 Britannias. Please also see the screen shot of the table I have uploaded, I compared the suspect tube of coins to another tube, I took 5 measurements of both diameter and width, as you can see there is some variance but these are only cheap calipers and so are not 100% bang on. My scales however cost me over £160, I took 5 weights of each coin and re-calibrated the scales after every 5 coins, you can also see the weights in the table. There were some that weight slightly under the 31.21g however as the difference was minute I chose to ignore these and focus on the coins that were considerably off. I have highlighted the 2 coins in question for easier reference.

All coins passed the magnet test, I am also going to carry out specific gravity and acid testing when I get a chance. Good pointer for the manetic speed tests I have never head of that one, I will definitely give it a try :).

As mentioned above I got them from thegoldbullion.co.uk, I am aware that this company is a little infamous due to their website being hacked (again they didnt get back to me then when I tried to enquire about what details were lost).

 

I really appreciate the help from you all.

Regards

Edited January 28, 2017 by perky416

[sixgun]

It says here

https://www.thegazette.co.uk/notice/L-60304-1693452

(a) a variation from the said standard weight of an amount per coin of 0.100 grammes;

(4) The least current weight of the said gold coin shall be 31.010 grammes.

[Kman]

1 hour ago, perky416 said:

As mentioned above I got them from thegoldbullion.co.uk,

I'm sure since they're from a reputable dealer they're fine, but as others have advised, loads of tests you can do to put your mind at rest

You could always take them to a jewelers and have them tested too, probably preferably via a machine rather than acid 

Always best to check your coins as soon as you get them; it's a lesson I too have learned 

 

 

[sovereignsteve]

2 hours ago, perky416 said:

Sorry I think you may have miss-read, its not over a gram shy at worst it is 0.07g from what the mint quoted me.

No, I don't think so, this is what you wrote:

On 27/01/2017 at 18:30, perky416 said:

I got in touch with the Royal Mint who advised that dimensions can vary slightly but as long as they all weight over 32.21g they are fine.

When weighing them (on the myweigh 250 scales) I found 2 of the coins to be fairly underweight coming in at 31.14g & 31.15g.

32.21 - 31.15 has always equaled 1.06 to my knowledge

Transcription error perhaps?

[sixgun]

The stack looks short - it looks like something is wrong but as i posted the lowest acceptable weight is 31.01g so all the coins are within the accepted range of weights.

The coin shown looks right enough.

I suspect most people don't have such a stack of gold Britannias to compare. Get them in capsules to protect them and enjoy.

Edited January 28, 2017 by sixgun

[Roy]

I think you're worrying too much, but then I don't hold 30k of Brits!

The weights seem correct for a 999 coin. It'a an ounce!

I don't know if this is improper, but to ease your mind perhaps pop into Atkinsons (Brum). Explain everything and ask them to test your coins.

Offer them a drink, or some 'dunking donuts'. They'll probably be as curious as you. Can't hurt to try?

Edited January 28, 2017 by Roy

[sovereignsteve]

Just what I was going to suggest. You should be able to find somewhere with a XRF scanner in Brum. Might cost you a couple of quid but that nowt when we're talking that amount of bullion.

[silversky]

The slide shown here is what you can make up at home.  This guy sells them in the USA.  Easy to make yourself and you can order flat rare earth magnets on amazon easy enough.  It's quite fun to play with and if you take different metals that are diamagnetic like copper silver or gold you see that they respond in the same way to the slide but slightly different relative to each other because of their different strengths of diamagnetism.   A standard plated brass fake roars down the slide at near free fall.  Silver, copper and gold slide gently due to the induced opposing magnetic field in them as they move through the strong field lines from the neodymium magnets.  It's immediately clear if a coin is a plated non diamagnetic material.  More care has to be exercised for a potentially plated diamagnetic metal like copper but it is still possible to compare to a known genuine gold or silver coin and see the speed difference between say a plated copper or other material coin.  The three metals all slide at very slightly different speeds so if you make up a nice long slide then you could time all your brits and compare.  An obvious difference in speed would be grounds for investigation.   Also, if it were as simple as a plated copper coin the coin would have to be huge to bring up the weight.

Just on the note about the SG test.  It's acceptable on silver coins because they are small enough to be hard to make a multilayer platter that balances out to be the right density for its volume and weight.  In gold it's less use because of the fact that tungsten is almost exactly the same density as gold and is therefore the element of choice for the robdogs to fill the centre of a bar with.  Much harder to do in a small coin so still worth conducting the SG test on a small coin as part of a series of other tests.  If they were able to make a Tungsten plated coin that passes the SG test, Tunsten is not Diamagnetic.  Its paramagnetic so would fail the slide test.  Combined these tests root out the fakes pretty well for coins.  As I said, bars are much harder to test at home and really require ultrasound testing to confirm no tungsten inside.   I used distilled water (de ionised water) when I did my SG tests just to keep things clean from any lime scale in the tap water. 

If you look up Tungsten "W" on the next link you can see that it's density is almost identical to gold "Au" at 19.25 and 19.3 respectively.  That is close enough that it's nearly impossible to test for that slight difference at home doing the SG test with basic scales.  That theoretically means that a tungsten coin plated in gold would weigh the right amount and measure the right amount.  However, Tungsten is not Diamagnetic but rather Paramagnetic so responds differently to a test of its magnetism.  http://www.periodictable.com/Elements/074/data.html

With Silver the SG test is much better for coins.  That is because there is no single element that is the same density as silver that could potentially be made into a coin and plated.  The SG of silver is in a zone all of it's own and so a clever series of plated materials would be required to match the overall density and for a single ounce of silver the effort and expense is way too much to justify.  That is obviously not true with gold because of the huge price difference so a decent loupe to examine is important.  I have come across a couple of silver fakes on ebay and with the loupe they are pretty obvious when compared to a genuine.  As a previous poster said, I'd pop into Atkinsons if you are near to them and ask for their help in testing electronically.  Even if they charge you for a bit of labour it will put your mind at rest which probably wont be otherwise.  I would avoid an acid test.  It only tells you what you know which is that the surface is gold which is not much use

Hope any of this helps and good luck. 

Edited January 30, 2017 by silversky

[sovereignsteve]

Is the slide really used with such a steep incline as the photo suggests?

[silversky]

Yes it is.  You need a reasonable amount of speed (imparted by gravity) to hit the sweet spot where the induced field in the coin is high and the surface friction effect is low.  If you have the slide too shallow, the amount of force induced is not high enough relative to the force of friction which becomes the predominant force resisting the coins movement.  That would be ok in a perfect world if friction was constant, but friction tends to be rather variable for a group of supposedly identical shapes and masses.  Tiny differences in the shape of a surface add up to large differences and the observation becomes more a measurement of differences in surface friction rather than of diamagnetic property.  Conversely, if the slide is too steep, ie near vertical, there is nothing to stop a coin from ever so slightly lifting away from the magnets which in turn reduces the strength of the induced field in the coin and allows the coin to travel faster like a non diamagnetic coin.  It's all about the sweet spot where the diamagnetism produces the predominant force resisting motion and it just seems to be around 70deg.  It would probably be different if you covered the slide with felt to prevent micro abrasions which I have considered doing.  If you make up one of these slides and play with it, the sweet spot becomes apparent and it's quite fun little experiment.  It feels a bit like the old cornflower and water trick.  Stirring slowly the spoon stirs easily but if you try to stir fast, the cornflower produces much more resistance and slows you down.

Cheers

[Pipers]

If they are heavy plated an acid test will not pick up a fake.  

Go to a dealer and get them to test them. 

£9500 worth of reasons to put your mind a rest

On 1/28/2017 at 18:20, Kman said:

I'm sure since they're from a reputable dealer they're fine, but as others have advised, loads of tests you can do to put your mind at rest

You could always take them to a jewelers and have them tested too, probably preferably via a machine rather than acid 

Always best to check your coins as soon as you get them; it's a lesson I too have learned 

 

 

This is what i would do if i was you.  Find a bullion dealer a good one and ask them to test the coins for you, remember you will be using their time up.     

 

[sovereignsteve]

2 hours ago, silversky said:

Yes it is.  You need a reasonable amount of speed (imparted by gravity) to hit the sweet spot where the induced field in the coin is high and the surface friction effect is low.  If you have the slide too shallow, the amount of force induced is not high enough relative to the force of friction which becomes the predominant force resisting the coins movement.  That would be ok in a perfect world if friction was constant, but friction tends to be rather variable for a group of supposedly identical shapes and masses.  Tiny differences in the shape of a surface add up to large differences and the observation becomes more a measurement of differences in surface friction rather than of diamagnetic property.  Conversely, if the slide is too steep, ie near vertical, there is nothing to stop a coin from ever so slightly lifting away from the magnets which in turn reduces the strength of the induced field in the coin and allows the coin to travel faster like a non diamagnetic coin.  It's all about the sweet spot where the diamagnetism produces the predominant force resisting motion and it just seems to be around 70deg.  It would probably be different if you covered the slide with felt to prevent micro abrasions which I have considered doing.  If you make up one of these slides and play with it, the sweet spot becomes apparent and it's quite fun little experiment.  It feels a bit like the old cornflower and water trick.  Stirring slowly the spoon stirs easily but if you try to stir fast, the cornflower produces much more resistance and slows you down.

Cheers

I remember someone making them up and selling on youtube. I think someone on here was acting as go between. I think they were covered in felt but don't remember them neing as steep.

[Bumble]

Nobody has mentioned the ping test yet. Balance the coin on the tip of your finger and tap it gently with a key or another coin. It should give a nice clear ring. Fakes don't sound the same. If in doubt, try a smartphone app like Bullion Test - it will compare the ring frequencies with the ones it expects and tell you whether it is fake.

[Pete]

I am surprised that coin 2 in your suspect batch is the thinnest yet amongst one of the heaviest.
That would indicate an error somewhere in your measurements as this is opposite to what would be expected.
Measuring coin thickness is almost impossible to your required precision because there will be variations in rim and profile ( cameo ) based on the stamping press and the wear of the dies. As all coin dimensions seem okay the weight is more critical and the simplest measurement to make. Electronic scales can however drift in readings and some are influenced by ambient room temperature and the surface the scales rest on so it would be worth remeasuring a few coins and compare against your published data.
Fakes are inevitably underweight AND oversize.

[Britannia47]

An interesting story of a miss reading by a Newbie who felt that some of his 30 1oz 2015 Britannias were fake leading to a wild goose chase in the wrong direction!  See if you can spot the error from over 5 years ago!  Well know posters were Sixgun, Sovereign Steve and Roy….

[Bratnia]

On 07/09/2022 at 19:50, Britannia47 said:

An interesting story of a miss reading by a Newbie who felt that some of his 30 1oz 2015 Britannias were fake leading to a wild goose chase in the wrong direction!  See if you can spot the error from over 5 years ago!  Well know posters were Sixgun, Sovereign Steve and Roy….

Care to share with a Newbie what the Newbie error actually was?

[Britannia47]

5 hours ago, Bratnia said:

Care to share with a Newbie what the Newbie error actually was?

I’ve had to refresh my memory on this one! 

If you read through this topic, you will find that perky416 who had purchased 30 1oz 2015 Britannias - over £30,000 pounds worth lined up his coins in 3 piles of 10 to find that one pile was shorter than the other 2. He suspected that 2 of the coins were thinner than the others. Alarm bells, are they fakes?!  Provided the’re 1oz RM said No! - See your dealer!  Perky then claims that he was told that an ounce needs to be 32.21, which is of course not true.   It’s 31.1035. These 2 coins were weighed and found to be 31.14 & 31.15g. and then immediately thinks they are underweight when in fact they were within limits. Although he had accurate scales the damage had been done, compounded by his ignorance of what 1 Troy oz should be in grammes….

I believe Perky was just an investor with no real knowledge of what he was buying which in the end led him astray. It may be a good idea for any newbie to do a bit of home-work on the specification of various gold coins IMO. Perky416 left TSF in Feb 2017!  1’m off to look at my new Sovereign that arrived this morning. 😀

[dicker]

And Perky was never seen again….

[JohnA1]

Whatever Perky's angle was - I, too, would be worried if a ten-coin stack was half a coin shorter than the stack next to it.🤔

I'd think being paranoid cautious is one of the reasons we engage in this pass time. Perky had some unexpected excitement🌡️