How to check gold purity at home

For as long as gold has been a part of human culture, it has been considered valuable and highly sought after. Because of this, history has witnessed countless would-be scammers trying to pass off less valuable substances as gold to profit from counterfeit treasures.

Jewellery is one of the most common vehicles for fake gold. It is more than possible that, at some point, you will come across fake gold jewellery if buying from private sellers or unscrupulous dealers.

Knowing how to tell whether or not gold is real and, as importantly, knowing how to check gold purity at home could save you both a lot of hassle and money down the line. Luckily, convincing fakes are incredibly difficult to make, thanks to gold's unique properties. What’s more, there are even a few simple tests that you can conduct at home to tell if your gold is the real deal.

Stamp or hallmark

The purity of gold is measured in karats, usually categorised by the numbers 24, 22, 10, 14, or 10. A 24-karat gold piece is comprised of 100% gold, which means that there is absolutely no alloy mixed into it.

The purity of gold can also be measured in percentages and parts per thousand. To convert karat into a percentage, you need to divide the karat number by 24 before multiplying the result by 100.

For example, this would mean that to find out the gold by percentage in a 22-karat ring, you would divide 22 by 24 (the result being 0.9166) before multiplying it by 100. This provides you with a result of 91.66, which would indicate that the piece is 91.66% pure gold.

One simple way to check gold purity is to look for the karat stamp on the jewellery piece.

Helpfully, it is mandatory for jewellers to mark both the hallmark and gold karat on each and every jewellery piece they create. With this in mind, you know that if your gold chain has "24K" mark stamped onto it, it means that the piece has a 99.9% gold content.

To help you understand your piece’s karat count, the following are some of the frequently used karat marks, including their corresponding percentages and respective parts-per-thousand values:

24K – 99.9% (999)
22K – 91.7% (917)
20K – 83.3% (833)
18K – 75.0% (750)
14K – 58.3% (583)
10K – 41.7% (417)

While stamps can be forged, they’re still the best indication you have that your gold is legit. Keep in mind that if you are buying gold that isn't stamped, it means that there is no guarantee that the piece you are purchasing is genuine.

Also, remember that gold-plated jewellery items may have karat stamps, but these only reflect the purity of the gold plates - not the entire piece.

Check its weight

One thing that works in gold’s favour and adds to its prestige is that it is rather difficult to imitate. One of the big advantages of pure gold is that it’s one of the densest metals on the planet and possesses physical properties that are incredibly hard to replicate.

The weight test applies primarily to bullion coins, as the weight of these can be easily checked against standard sizes. With jewellery, however, a piece feeling too light is likely indicative of it being either low in karat, plated, or fake.

This means that any metal used to copy pure gold jewellery will likely be much less compact, as it would take more material to replicate a similar weight of gold. With 7879’s guaranteed 24-karat gold, on the other hand, you know that whatever the piece weighs is the exact weight of gold you’re buying.

The magnet test

Our second simple method for checking the purity of your gold is the magnet test. This is another straightforward test you can carry out at home as it requires a minimal amount of equipment.

Unlike many other metals, gold is not magnetic. This means that any authentic, pure gold bullion, coin, bar, or jewellery will not stick to or be affected by a magnet.

You can try this test at home with any reasonably strong magnet by attempting to pick your gold jewellery up with it. If you are able to pick the piece up, you know that your coin, bar, or jewellery is made from (or at least contains) one or several other metals. Care should be taken with this method, however, as gold is not the only non-magnetic metal, and a fake coin could still pass this test.

Conversely, it is always important to bear in mind the purity of the gold you are testing. Gold that is 24 karat is 99.9% pure and, therefore, should not be magnetic. The presence of other metals in jewellery of varying karatage could cause the piece to become magnetic.

Jewellery is almost always made from a gold alloy, as opposed to being pure, so your jewellery could contain more other metals than it does gold. For this reason, we recommend you use the magnet test alongside one (or several) of the other tests mentioned in this article and take any findings only as an initial guide.

The “ping” test

The “ping” test, as it is commonly known, is another gold purity check that informs us if a piece of jewellery is made from genuine or fake gold. This test simply requires you to listen to the sound the metal produces when struck.

Precious metals will always make a long, high-pitched ringing sound when struck. Compare this to other base metals, whose respective sounds will be considerably duller and much shorter.

Balancing your piece of jewellery on the end of your finger and tapping it with a coin should be enough to garner a ringing sound. When struck, the difference between a piece of jewellery made from pure gold and one made from a non-precious metal should be quite obvious.

If it doesn’t have that clean, high-pitched ring, then it isn’t the real thing.

The ceramic test

Our third idea for how to check the purity of gold is the ceramic test. By simply dragging your gold over a ceramic plate, you’ll discover another quick and uncomplicated way to test your gold’s authenticity.

To execute this straightforward method, simply draw your gold across an unglazed ceramic plate, applying slight pressure in the process. The gold is likely real if you can see a gold mark on the ceramic once you've done this. If the mark is black, however, then you know that the gold is probably fake.

Bear in mind that you do run the risk of doing a small amount of damage to your piece through this method, but a small amount of polish should be enough to repair any minor marking.

The magnifying glass test

So, you've tried the magnet test and, the ping test. But what if we told you there's another, less risky, method to add to your gold-checking toolkit? Enter the magnifying glass test. It's as straightforward as it sounds but can reveal a wealth of information about your gold piece.

To start, grab a magnifying glass—any will do, but one with at least a 10x magnification is ideal. Make sure your gold piece is clean; you don't want smudges or dirt to mislead you. Find a spot with good lighting; natural daylight works wonders but a well-placed lamp can do the trick too. You’re looking for:

Discolouration: Real gold doesn't like to change its colour. If you're seeing shades that remind you more of a chameleon than a gold bar, you might want to question its authenticity.
Spotting: Gold shouldn't play hide and seek. If you see spots where the colour seems to be hiding or changing, it's a sign you might not be dealing with the real deal.
Surface quality: Gold is smooth. It's one of the reasons we love it so much. If your piece has a surface that looks like it's been through a rough time, it might be telling you something.

The makeup test

The makeup test is a lesser-known but surprisingly effective way to check if you're dealing with the real McCoy or a gilded imposter.

First, you'll want to swipe a bit of liquid foundation or face powder on the back of your hand. Make sure it's evenly applied. Next, rub your gold piece across the makeup. This is where the magic happens—or doesn't, depending on what you've got.

If your gold is genuine, the makeup will retain its original colour. Gold is a noble metal and doesn't react easily with other substances. But if you see a black streak, that's a telltale sign you might be dealing with a less-than-pure piece. Gold imposters contain other metals that can react with the makeup, leaving a visible mark.

While this test is a handy trick to have up your sleeve, it's not foolproof. Some high-quality fakes have been known to pass the makeup test, and conversely, some genuine but lower-karat pieces might leave a faint streak. So, consider this method as more of a first step in your investigative journey rather than a definitive conclusion.

The float test

Gold is a dense metal, denser than most things you'll encounter in your daily life. So, if you drop a piece of genuine gold into a bowl of water, it should sink faster than jewellery made from less-dense metals. Many fakes will float or sink more slowly, revealing themselves as frauds.

But here's the rub: while this test is as easy as pouring a cup of water, it's not the most reliable. Other metals can mimic gold's density, and some sophisticated fakes are alloyed in a way that mimics gold's specific weight. So, if your piece passes the float test, don't break out the champagne just yet. Consider it a promising sign, but one that should be confirmed with other methods.

The vinegar test

If you're looking for a simple yet effective way to test your gold with tools you already have at home, white vinegar comes to the rescue. To perform this test, place your gold item in a bowl and pour enough white vinegar to cover it. Let it sit for about 15 minutes before carefully observing any changes in colour.

If the gold remains its original hue, you're likely in possession of a genuine gold piece. On the other hand, if you notice discolouration, it's a strong sign that the item is not pure gold.

Again, this test might be easy to carry out, but it’s also not foolproof, so use it with discretion.

The nitric acid test

The final (and least straightforward) of these tests is the nitric acid test.

The nitric acid test is the riskiest of the tests in this article, primarily because it could see you damaging your jewellery permanently. That is unless, of course, your jewellery is actually comprised of pure gold.

The premise behind this test is that gold is resistant to oxidation and corrosion. Therefore, pure gold will not be affected by the acid. Different strengths of acid are available to test different karats, so gold that doesn't react to the acid is at least as pure as the karat rating suggested, if not higher.

Conversely, if you unsuccessfully apply acid intended for 22-karat gold to your 24-karat piece of jewellery, you know that your gold is 22-karat gold at best, and maybe not even gold at all.

Take your gold to a reputable jeweller

While at-home tests can give you a good idea of your gold's authenticity, nothing beats the precision of professional testing. If you're looking to be absolutely certain about your gold's purity, taking it to a reputable jeweller is the way to go.

Jewellers have access to specialised equipment that can provide a more definitive answer. Some of the advanced testing methods they might use include:

XRF Spectrometer Machine: This device uses X-ray fluorescence to determine the elemental composition of the gold, offering a highly accurate assessment of its purity.
Electronic Tester Machine: This machine measures the electrical conductivity of the gold to verify its karatage.

So, if you're in doubt or have a piece that's particularly valuable, a trip to a trusted jeweller can provide the peace of mind you're looking for.

How to avoid buying fake or low-quality gold jewellery

The best defence against ending up with fake or low-quality gold is to take preventative measures right from the start. One surefire way to ensure you're getting what you pay for is to buy from a reputable dealer.

These dealers are equipped with advanced gold-testing machines that offer a highly accurate and non-destructive way to verify the purity and authenticity of the gold. This means you can skip the at-home tests and rest easy knowing your investment is sound.

But even before you make a purchase, it's crucial to be aware of common scams in the gold market. For a detailed rundown of what to watch out for, check out our article on the most common precious metals scams. Knowledge is power, and being informed can save you from making a costly mistake.

So, if you're in the market for gold, opt for a certified 24-karat gold or pure platinum retailer like us at 7879. We specialise in these high-purity metals, ensuring that what you see is exactly what you get. With these precautions, you can invest in gold jewellery with confidence, knowing it's of the highest quality.

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