Gold testing for a Newbie

[ABW246]

Hi, as a newbie to test my coins I simply rely on measuring and weighing, and trying to stick with people with a good reputation. 

 

I've seen the expensive electronic gadgets for testing, expensive being the operative word. Other than that I only know about acid testing (not actually in practise!)

 

What inexpensive methods of testing is there? And what do people think of acid testing bullion coins? 

Edited September 7 by ABW246

[Petra]

Just stick to your first methods and leave the acid in the bottle. Who were you thinking of selling your acid tested coins to?🤔🤔

[ABW246]

1 hour ago, Petra said:

Just stick to your first methods and leave the acid in the bottle. Who were you thinking of selling your acid tested coins to?🤔🤔

Thank you for the advise. I'm actually not thinking of selling any for the next 10yrs. I want to know how others test coins for piece of mind!

[Petra]

1 hour ago, Petra said:

Just stick to your first methods and leave the acid in the bottle. Who were you thinking of selling your acid tested coins to?🤔🤔

Also use a molybdenum magnet or water density tests🤔😮

[James32]

Keep acid for inconspicuous areas of jewellery, never on coins.

Stick with trusted sellers, you're  effectively buying their experience too.

1) magnet test 

2) weigh

3) dimensions check with callipers 

4) ping test

If you have passed all these, then your in good shape, a fake can fool one of these steps, but would be a rare occurrence to fool them all.

If you still have any niggling doubts...

5) specific gravity test ( check YouTube )

Edited September 7 by James32

[ABW246]

11 minutes ago, James32 said:

Keep acid for inconspicuous areas of jewellery, never on coins.

Stick with trusted sellers, you're  effectively buying their experience too.

1) magnet test 

2) weigh

3) dimensions check with callipers 

4) ping test

If you have passed all these, then your in good shape, a fake can fool one of these steps, but would be a rare occurrence to fool them all.

If you still have any niggling doubts...

5) specific gravity test ( check YouTube )

Thank you so much for that. The specific gravity I didn't know. I'm off to YouTube!

[Petra]

22 minutes ago, ABW246 said:

Thank you so much for that. The specific gravity I didn't know. I'm off to YouTube!

😮oh no….😮😁

[Bratnia]

5 hours ago, Petra said:

Also use a molybdenum magnet or water density tests🤔😮

What is a molybdenum magnet?

I believe advice is to use a strong magnet that's the same size or larger than the coin being tested (flip the coin and test both sides) so for up to 1 ounce Britannia coin size maybe this 40mm version?

How should a magnet be stored?

For scales maybe something like this?

And a

When balancing a coin on the tip of your finger to perform a ring test, what do you strike it with? Another coin? Britannia's are (near) solid gold and will dent/scratch more easily than Sovereigns

And should you wear gloves?

 

 

 

[Bratnia]

The more pure the gold the shorter the 'ring'. 22c has a nice persistent higher pitched ring, 24c Britannia can sound more like a oh no possible dud (deeper shorter ring) by comparison. Comparison against known good same coin helps focus the ear.

 

Not sure, but looks to me like using another coin to perform the ping test may have dented the coin. Use just a gentle/delicate tap not a bash

 

Edited September 8 by Bratnia

[Bratnia]

17 hours ago, James32 said:

If you still have any niggling doubts...

5) specific gravity test ( check YouTube )

... or just walk

[silversky]

SG test is only really helpful on silver.  The reason is that Silver has a distinct SG which means that clever alloys or multi material platters would need to be used to mimic this SG. and that would make the counterfeit more expensive than Silver itself.

Gold on the other hand has a nearly identical SG to Tungsten, and Tungsten is many times cheaper so it pays to plate Tungsten in gold and pass it off as Gold.  Gold is 19.3g/cm3 and Tungsten 19.25g/cm3.  This is inside the margin of error for your usual kitchen equipment, which makes the test useless against Tungsten which is the primary counterfeit method.

Silver is around 10.49g/cm3 and no other element or compound which is cheap is of similar density.  Silver stands alone at this density, which means it can be reliably tested for by using this method.  Even with poor technique and only basic kitchen equipment, it is possible to be confident that an item which comes in close to 10.49 is in fact Silver.  The same cannot be said for Gold.