# Lifestyles & Discussion > Personal Prosperity >  spotting fake gold and silver coins/bullion

## cbc58

How can you tell if gold or silver coins/bullion you are buying from an individual are real or not?   Seems like this could be a big issue moving forward if you decide to buy from other than a dealer....

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## noxagol

Density tests, that is, finding the volume and dividing by its weight. Silver and gold rings pretty good when struck a very distinct high pitch ring.

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## Dr.3D

People used to bite down on gold coins to see if they could put tooth marks in the coin.

Gold is very soft and easy to put toothmarks in.  Don't try this if you have bad teeth.

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## Acala

> People used to bite down on gold coins to see if they could put tooth marks in the coin.
> 
> Gold is very soft and easy to put toothmarks in.  Don't try this if you have bad teeth.


I used to think this.  Then I read that people would bite on a gold coin to test if it was lead covered with gold leaf.  Lead is the only common metal anywhere NEAR the density of gold and it is very soft.  If the bite made a mark, it was fake.  It is true that gold is also very soft as a pure metal, but gold coins minted for circulation were never pure gold - they are always alloyed with silver because pure gold will wear too fast.  So a true gold coing alloyed with silver is not goign to show a bite mark.

The best way to test gold is, as the prior poster indicated, measure its density.  There is no way to fake that because anything more dense than gold is also more rare.  Unfortunately, the density of silver CAN be faked using lead inserts.  I don't know any easy way to tell.

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## cbc58

when you say measure it's density I think you are saying check how much it weighs...

if this is the case, is there a list of gold coins and how much they are supposed to wiegh?  for example:  a 2002 gold eagle should weigh 31.2 grams or something like that?

i can see alot of people getting burned if they are not careful.  I don't want to be one of them.

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## Dr.3D

The problem with a density test is, if some coins are not 0.999 or better purity, you may get a false reading on your test.   Many coins have some copper in them to make them harder.  This will of course change the density of the coin.

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## Dr.3D

> when you say measure it's density I think you are saying check how much it weighs...
> 
> if this is the case, is there a list of gold coins and how much they are supposed to wiegh?  for example:  a 2002 gold eagle should weigh 31.2 grams or something like that?
> 
> i can see alot of people getting burned if they are not careful.  I don't want to be one of them.


Density is not just weight but how much displacement an object has.
The first check for density was to see how much water the object displaced and then weigh the object to see what the ratio was.  It is about the weight of the object and the volume it has.

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## robert4rp08

> when you say measure it's density I think you are saying check how much it weighs...
> 
> if this is the case, is there a list of gold coins and how much they are supposed to wiegh?  for example:  a 2002 gold eagle should weigh 31.2 grams or something like that?
> 
> i can see alot of people getting burned if they are not careful.  I don't want to be one of them.


Weight (mass) is not enough to determine if it's fake or not. You have to know the size (volume) also.  For example, a chunk of lead coated in gold could weigh 31.2 grams and you'd think it was pure gold based on appearance (color) and weight.  However, if you look at the size of that chunk of lead it would be smaller than a 31.2 gram chunk of gold.

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## TheEvilDetector

Quick google search.

http://www.igem.com/c-3-gold-testers.aspx

RS Mizar M24 Electronic Gold Tester
- advanced electronic gold tester, capable of distinguishing gold contant between 9K and 24K

RS Mizar M24 Electronic Gold Tester - Indispensable tool for jewelry professionals, jewelry lovers, flea market visitors and for the rest of us, whenever we are not 100% sure. One error may cost more than the price of this tester!

Electronic gold tester is easy and safe to use - no messy acids involved.
Everything is included to start testing immediately.

The most advanced gold tester in the world, the M24 precisely determines gold karat values equal to or greater than 9K, 10K, 12K, 14K, 16K, 18K, 20K, 22K, and 24K.
Battery operated and comes with a full one year warranty.

Features:

    * Tests gold from 9 to 24K
    * Tests ALL color gold alloys
    * Non-destructive testing
    * Distinguishes gold flash and gold plate from solid gold
    * Determines platinum
    * Shuts off automatically to increase battery life
    * Tests in as little as two seconds
    * Advance technology - patents 5080766, 5128016



The solution that it works with:


Instructions for use here:
http://www.rsmizar.com/M24OM.htm

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## Dr.3D

Here is an older thread about this subject.  It might help to shed some extra light here.
http://www.ronpaulforums.com/showthread.php?t=128798

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## Dr.3D

> Weight (mass) is not enough to determine if it's fake or not. You have to know the size (volume) also.  For example, a chunk of lead coated in gold could weigh 31.2 grams and you'd think it was pure gold based on appearance (color) and weight.  However, if you look at the size of that chunk of lead it would be smaller than a 31.2 gram chunk of gold.


Actually, the chunk of lead would be bigger.

http://www.allmeasures.com/Formulae/...u%5D&formula=2

http://www.allmeasures.com/Formulae/...b%5D&formula=2

Using those two pages you can see the difference between gold and lead.

1 gallon of lead weighs 94.64 pounds.
1 gallon of gold weighs 161.07 pounds.

Edit: Or to put it another way...

31.2g of gold = 1.66 ml volume.
31.2g of lead = 2.83 ml volume.

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