Ways to test Gold

[silvernewbie]

Hi

i am being offered Gold at prices slightly too good to be true, what is the best way to test it is genuine?

Is the magnet and dropping it in water test enough?  Or do i need to buy some acid? 

thanks

[HelpingHands]

3 hours ago, silvernewbie said:

Hi

i am being offered Gold at prices slightly too good to be true, what is the best way to test it is genuine?

Is the magnet and dropping it in water test enough?  Or do i need to buy some acid? 

thanks

 

[silenceissilver]

A specific gravity test, combined with a magnet test will determine if it's gold with practically 100% certainty, at least for a small (thin) piece of gold. Even for a big, fat bar it will give you a very good indication but in theory a fat bar could still be forged, despite these two tests. What kind of piece of gold is it and how big?

The reason for the difference in certainty is the different ratio between volume and surface between small and big pieces or rather simply the thickness. If there is a layer of real gold on the outside, the magnet will act as it should but it could still be a mixture of metals inside that have the same average density as gold. Whereas for a thin bar, the real layer of gold would be too thin for the magnet to act as it should, if it had a core of a different composition. All in all, the likelihood that it's real is very high even for big bars, with both tests combined, though.

However, carrying out a magnet test is quite tiring because the effect is not big. It's much easier done for silver. If you slide a small neodymium magnet down the gold coin, you will hardly be able to determine if there was an effect. Ideally, you'd want to hang it on a thread, make sure it's 100% still and get a neodymium magnet that ideally (but not necessarily) is at least roughly the same size as the piece of gold, close to the gold coin and see what it does.

Edited February 3, 2021 by silenceissilver

[silvernewbie]

Thanks! I did the water test it went straight down, i used a normal small fridge magnet and couldnt feel any pull and i used white vinegar and soaked the coin for 15min..no obvious discolouring, a slight mark but think this was already there.  

[silvernewbie]

A 1oz 2013 brit

[HelpingHands]

I assume you've weighed and measured it too?

I think that year had the larger diameter than the following years

https://www.chards.co.uk/2013-gold-britannia-one-ounce-bullion-coin/2613

 

[daca]

3 hours ago, silvernewbie said:

I did the water test it went straight down

Really, did you expected a coin (off any metal)  to float 🧐

[silvernewbie]

9 hours ago, HelpingHands said:

I assume you've weighed and measured it too?

I think that year had the larger diameter than the following years

https://www.chards.co.uk/2013-gold-britannia-one-ounce-bullion-coin/2613

 

Theres x2 2013 coins , just a slight difference in weight, does this sound ok?

[HelpingHands]

Coins do vary slightly.  

I don't see any problems but I don't own that coin to compare with.

[Pete]

On 03/02/2021 at 01:31, silvernewbie said:

Thanks! I did the water test it went straight down, i used a normal small fridge magnet and couldnt feel any pull and i used white vinegar and soaked the coin for 15min..no obvious discolouring, a slight mark but think this was already there.  

Sorry to advise but these tests are a total waste of time and may be giving you false security.

[silvernewbie]

13 minutes ago, Pete said:

Sorry to advise but these tests are a total waste of time and may be giving you false security.

Thanks, i realise counterfeits could easily pass these tests.  I took it to a local dealer he looked at it with his eye glass and said it looked real, so i am confident overall, just the price was too good to be true hence my only suspicion!  I will have to get some acid for the future And do the scratch test £25 from amazon

On 03/02/2021 at 05:13, daca said:

Really, did you expected a coin (off any metal)  to float 🧐

It said online a fake Gold coin will slowly fall/hover at the bottom! 

[sovereignsteve]

3 hours ago, silvernewbie said:

It said online a fake Gold coin will slowly fall/hover at the bottom! 

if it's made of aluminium maybe and about half the weight it should be.

Far easier to weigh it on accurate scales, they are cheap enough on ebay, and measure it's diameter and thickness. That's why coins are the best way to go, it's easy to find the true weight and dimensions in reference sources. Compare the measured against the reference and you'll soon spot the fakes. Well most of them, but if it's just bullion as opposed to numismatic, you're highly unlikely to find any fakes that aren't obvious from the weight etc.

 

[silenceissilver]

26 minutes ago, sovereignsteve said:

if it's made of aluminium maybe and about half the weight it should be.

Far easier to weigh it on accurate scales, they are cheap enough on ebay, and measure it's diameter and thickness. That's why coins are the best way to go, it's easy to find the true weight and dimensions in reference sources. Compare the measured against the reference and you'll soon spot the fakes. Well most of them, but if it's just bullion as opposed to numismatic, you're highly unlikely to find any fakes that aren't obvious from the weight etc.

 

From my own experience I find that pretty inconclusive.

It's in German but just looking at the video gives you an indication of how close good forgeries can get to real gold. You do see him measure it the way you suggest but it's really a very close call - or rather no call, at all. He doesn't do the magnet test though (from what I remember) and the forgeries are made of tungsten (from what I remember). 

 

4 hours ago, Pete said:

Sorry to advise but these tests are a total waste of time and may be giving you false security.

I have never heard of this test but for sure it doesn't sound convincing, at all. I thought he meant a specific gravity test, first.

[silenceissilver]

4 hours ago, silvernewbie said:

!I will have to get some acid for the future And do the scratch test £25 from amazon

I won't buy that coin from you. Not sure how many other people will. You might risk only getting melt value for it, thus considerably less. Also, it only tests the surface.

[sovereignsteve]

ah yes tungsten. that's why I don't buy 1 oz coins, but I believe the ping test should spot these.

[silenceissilver]

8 minutes ago, sovereignsteve said:

ah yes tungsten. that's why I don't buy 1 oz coins, but I believe the ping test should spot these.

A magnet test will spot them, too. Here, one possible set-up (sorry, again in German but you can turn the sound off, you see everything you need to know, it's basically what I have described in my first post in this thread - gold gets pushed away, tungsten gets drawn to the magnet)

 

[Pete]

If a simple magnet test would confirm tungsten then the banks holding vast quantities of bars would neither cut them in pieces or drill through them to verify.
Since tungsten is such a hard material unlike gold which is very soft, I cannot imagine a counterfeiter technically capable of manufacturing a fake coin.
A plain bar yes.
As for acid tests this only tests the outer surface or as deep as you dare file.
A good fake bar or coin ( containing base metal not tungsten ) will have a thick plate of gold perhaps 1/10 mm so defeating the acid tests and maybe other cheaper instrument tests.
A fake one ounce Britannia will have the correct diameter and if it is the specified weight, it will be maybe 10% thicker in the centre - avoid measuring the rim.
Diameter, weight and thickness all within spec then it will be gold.
Specific gravity test as backup but making accurate measurements is tricky unless you know precisely what you are doing.
I spotted a fake sovereign and was able to determine that the coin was not 22ct but 19ct, a jeweller's copy.
it was purchased from one of our very well established dealers who confirmed and replaced so the SG test if done correctly does work - but I was a scientist once.

[Isitreal]

Had one of these bad boys come through the letter box today, just in case I come across any when the boot sales open. the 3 way test seems to work spot on.

[LawrenceChard]

On 04/02/2021 at 19:28, silvernewbie said:

Thanks, i realise counterfeits could easily pass these tests.  I took it to a local dealer he looked at it with his eye glass and said it looked real, so i am confident overall, just the price was too good to be true hence my only suspicion!  I will have to get some acid for the future And do the scratch test £25 from amazon

It said online a fake Gold coin will slowly fall/hover at the bottom! 

It also says online that Donald Trump won the 2020 US Presidential election, giants lizards control the world, Covid vaccinations contain microchips, the 1969 moon landing was fake, Covid-19 does not exist, 5G phone masts give you Covid, silver will imminently crash to $4, and gold drop to $400 (and these last two were on TSF!)

🙂

[SilverStorm]

Unless you have testing equipment to confirm validity of a metal, it’s best to bring the coin in question to a reputable coin dealer to help you determine if the coin is genuine or fake. 

[Bigmarc]

56 minutes ago, LawrenceChard said:

It also says online that Donald Trump won the 2020 US Presidential election, giants lizards control the world, Covid vaccinations contain microchips, the 1969 moon landing was fake, Covid-19 does not exist, 5G phone masts give you Covid, silver will imminently crash to $4, and gold drop to $400 (and these last two were on TSF!)

🙂

They are all on the TSF. 

[LawrenceChard]

On 02/02/2021 at 20:14, silvernewbie said:

i am being offered Gold at prices slightly too good to be true, what is the best way to test it is genuine?

Is the magnet and dropping it in water test enough?  Or do i need to buy some acid? 

thanks

If you are "being offered Gold at prices slightly too good to be true", then they are not true, and you don't need to even think about any tests.

🙂

[LawrenceChard]

1 minute ago, Bigmarc said:

They are all on the TSF. 

All?

That's bad news!

🙂

[DukeSilver]

I will say this: the day my Sigma Metalytics machine arrived, I felt like a huge weight had been lifted off my shoulders.

Even though it seems like a huge investment for such a small device (which it is), I take solace in the fact that I can always be confident in my gold and silver purchases.

By the time it catches 2-3 fake sovereigns (so far, not yet) I will consider it to have paid for itself!

Plus, if you look after them, these machines tend to retain their value on the second-hand market.

[SilverStorm]

On 12/07/2021 at 09:43, DukeSilver said:

I will say this: the day my Sigma Metalytics machine arrived, I felt like a huge weight had been lifted off my shoulders.

Even though it seems like a huge investment for such a small device (which it is), I take solace in the fact that I can always be confident in my gold and silver purchases.

By the time it catches 2-3 fake sovereigns (so far, not yet) I will consider it to have paid for itself!

Plus, if you look after them, these machines tend to retain their value on the second-hand market.

Agree DukeSilver.  For anyone who is serious about stacking PMs, it behooves you to invest in testing equipment to confirm the authenticity of your PM.  Which is why I will always advocate equipment purchase first and foremost.  

Having said that, it's also important to not completely rely on the Sigma machine without cross testing with other known testing methods to confirm validity.   Fraudsters are getting smarter and smarter in making fake PM, and we need to use more testing methods as well as logic and common sense to prevent fakes from entering into our stack.

Edited July 15, 2021 by SilverStorm