How to Tell if Gold Is Real – 11 Tests for Gold Purity

Gold FAQ - December 5, 2021

If happens all the time: you have some gold jewelry around the house – at least it looks like gold – but you’re not sure if it’s real to begin with, and if it is you don’t know if it has a high gold purity or if it’s mostly metal alloys. Knowledge is power here, as it has everything to do with the value of the pieces.

So how do you know if your gold is real?

And if it’s real, how pure is it?

And how much does it weigh?

And with all that information, what is it worth and what can I expect to be paid for it?

All fantastic questions. At Express Gold Cash, it’s vital that we’re able to tell the real from the counterfeit gold. We’ve seen fake gold in many forms, from bars to pieces of jewelry and everything in between.

 If you are looking to sell some of your gold pieces, or you are looking to sell some estate jewelry that you inherited, there are a few ways that you can determine if what you have is real or fake.

1. Use a Metal Analyzer

Gold Metal Analyzer - Test the Purity of Your Gold
XRF Niton XL2

The most reliable way to check if a piece of gold is real or not is by using a testing machine. It allows you to separate the genuine from the fake without causing any damage to your piece. It also tells you the exact purity of the gold in just a couple seconds.

At Express Gold Cash, this is what we use to determine the purity of your gold pieces. There’s no guesswork involved, so we can easily understand the value of your gold and quote you a fair price for it.

The XRF spectrometer is an x-ray instrument that can identify the chemistry of a substance by measuring the secondary x-ray it emits after being subjected to a primary x-ray beam. 

Above is a picture of the XRF Niton XL2 we use at Express Gold Cash to measure the purity of your gold. The product by Thermo Fischer costs tens of thousands of dollars, and even used ones you can find online start around $20k. So it’s probably not feasible for you to purchase one.

That said, if you send your gold to Express Gold, we’ll test your gold for free with no obligation to sell to us (but we will provide you with an offer for your gold of course).

A scientific method like this is the most fool-proof way to accurately measure purity and authenticity. Other methods are a bit more dubious, and there’s less trust in them.

2. The Float Test

Float Test for Gold Authenticity

Not everyone has access to testing machines, and many do not have the budget for one, especially if it is just for personal use. If you belong to this group, don’t worry, there are other things that you can do to check if your jewelry has real gold or not. 

One example is the float test. It is as simple as it sounds. All you have to do is get a glass of water, place your gold piece in it, and see if it floats. If it does, then it isn’t real gold. If it goes straight to the bottom or hovers near it, there is a chance that you are holding real gold in your hands. This is obviously not 100% foolproof, but it gives you a preliminary way to check your piece.

It’s a fast and easy way to identify a piece as obviously fake, but if it does sink then additional testing would be required to determine the authenticity.

3. Finding the Gold Purity Stamp

Real gold is often stamped with a purity marketing

If you have a magnifying glass at home, you could also try looking for an engraving somewhere on the piece of jewelry. It is a mark left by the manufacturer to identify itself or the purity of the piece.

You could also look for letter markings that indicate whether the piece is gold-plated (GP), gold-filled (GF), or gold-electroplated (GE), which means that they have a very small percentage of gold.

You may also find a number that represents the purity of the gold. The numbers generally represent the percentage of gold in the piece. A few of the common ones include:

Generally speaking, this is also a great way to tell the purity of real gold. Of course, markings like this can be faked. So you should always run additional tests or consult a professional to make sure these are markings on a genuine piece.

However, if you’ve run other tests and determined that you do in fact have real gold, then the marking on the gold will be a good indicator of purity.

If you have estate jewelry or old gold that has been in the family for a long time, you can be pretty confident that the stamp markings are legitimate.

4. Test It On Your Skin

Oxidized skin test for gold

Another crude but somewhat effective way to tell if the gold is real is by simply letting it touch your skin. If it leaves a blue, green, or purple discoloration, this means that it was oxidized, which happens only if it is not gold. Just make sure that you do not have any traces of foundation on your skin before you do this.

5. The Scratch Test

The scratch is a bit more accurate but is still fairly easy to do. All you need is a piece of unglazed ceramic or tile small enough to hold in your hand. Use it to scratch the surface of the piece you are trying to test. If it leaves a black marking instead of a gold one, then the piece is not real. 

Real gold could not be “scratched” by something like this.

If you are going to do this test, find an inconspicuous spot to scratch and make sure that you do not damage the piece.

6. Test The Weight and Density

If you are familiar with the story of Archimedes and how he checked if the crown was made of pure gold, then you get the idea of this test. Simply weigh your piece, check the volume of water that it displaces (a beaker works best), and calculate its density.

If it is close to 19.3 grams for every milliliter (or a percentage of it, depending on the declared purity), then you have a real gold piece. 

Of course this will require a pretty exact measurement for a small piece of jewelry. That makes the confidence behind measures like this better left to the Greek Myths.

7. The Magnet Test

Do you have a strong magnet at home? If you do, you can use it to test if your piece is real gold. 

Simply put, gold is not magnetic. If the sample gets attracted to the magnet, it is not real. However, if it does not react to the magnet, this does not automatically mean that it is gold since other metals are also non-magnetic. 

Again, it’s a way to quickly determine that a piece of gold is fake, but won’t ensure its authenticity.

8. The Nitric Acid Test

Gold is a noble metal, along with platinum and silver. One of the characteristics of this group of metals is that they are resistant to acids. Other metals will melt when exposed to the chemical, but not gold, which makes this test fairly effective in weeding out the fake. 

If you have a drain cleaner or descaler at home, you should be able to do this test. Make a small scratch on the piece and pour the nitric acid on it. If it turns milky white or green, then what you have is not real gold. Just be careful if your piece of jewelry has ornaments that are not made of gold, like cremation jewelry, for instance, as they could get damaged.

9. The Vinegar Test

If you do not have access to nitric acid, you can use vinegar instead. The idea is pretty much the same — find a discreet spot to make a scratch, then add a few drops of vinegar. If it reacts, then it is a fake. Otherwise, there is a good chance that it is real.

10. Gold Testing Kits

If you’re willing to invest a little bit of time and money into testing for the purity of your gold (but don’t have $25k to drop on a metal analyzer), there are at home testing kits that are more accurate than the simple scratch and acid tests. These provide more advanced testing that would allow you to determine the purity of your gold pieces.

Here is an example of a well-reviewed gold testing kit from Amazon.

While their detailed instructions will be of more help, essentially it’s an advanced scratch test with different fluids to more specifically test different gold purities for reactions. Certain fluids will only react at a certain purity, so by process of elimination you can determine what the purity of your gold pieces are.

You can also find many videos on YouTube showing this testing process.

This is a nice “do it yourself” way to test your own gold if you’re curious, or if you just want to learn about the alloy components of gold purity. Science is fun! But as always, if you’re looking to buy or sell any kind of quantity of gold, it’s best to have a professional look at it. That said, knowledge is power, so if you have an idea of the purity before taking it to a jeweler, you can make sure you don’t get ripped off by an unscrupulous or uninformed buyer.

11. Take It to the Jeweler

Jewelry testing gold purity

For some of these tests, the results are not guaranteed, which means that fake metals could still pass them. If you want to make sure that you have a genuine piece but do not have access to testing machines, then go to a reputable jeweler near you. Experienced jewelers have the skills, experience, and tools needed to get the job done without leaving any room for doubt. 

At Express Gold Cash, we have the tools to quickly and confidently provide you with the purity and weight of your goal to help you understand the value of your pieces. Some local jewelers can likely provide a similar service for you.

For Your Peace of Mind

Gold is one of the most sought-after metals in the world. Sadly, it is also the focus of many counterfeiters. Protect yourself and your hard-earned money from fake gold pieces by having your gold professionally evaluated, and only buy gold from reputable companies or if the gold has been thoroughly and professionally tested.

Want to have your gold tested? Request a kit from Express Gold Cash now!