How To Test Gold At Home With Toothpaste: A Simple Guide

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Last Updated on: 19th November 2025, 11:11 am

Gold is a precious metal with a long history of being used as currency, jewelry, and other decorative items; it’s known as one of the most stable and inflation-proof investments historically. Gold is also an excellent conductor of electricity and heat, so it’s often used in electronic devices like cell phones and computers.

Many people have gold sitting in their homes in the form of jewelry and other keepsakes. So, how do we know if the gold we have is real? That’s where gold testing comes in. By running a simple test, we can determine whether the gold is pure or not.

There are a few different ways to test gold, but one of the most common is to use toothpaste. (Yes, toothpaste!) 

Let’s take a look at the process.

Gold Testing with Toothpaste

Important: At-home tests like toothpaste, magnets and float tests can sometimes help you spot obvious fakes, but they are not definitive. They can also damage your jewelry if done incorrectly. For valuable items, always confirm results with a professional jeweler or assayer.

To test gold with toothpaste, you will need the following items: a small piece of gold, toothpaste, and running water.

1. First, you’ll need a small piece of gold to test. It can be a coin, a ring, or anything else made of gold.
2. Next, apply a small amount of toothpaste to the gold piece. Be sure to use plain white toothpaste; avoid any with colored stripes or other added ingredients.
3. Rub the toothpaste onto the gold for about 30 seconds. You should see a black streak begin to form.

Source: Ruth Capio

4. Rinse the gold piece under running water. The black streak should disappear, leaving the gold clean.
5. If the black streak rinses away cleanly, it can be a sign that your piece behaves like real gold. If the dark mark stays or the surface looks discolored, it may indicate a lower-quality alloy or plating. However, this is only a rough screening test and not a definitive proof of authenticity.

While this test is not 100% accurate, it can sometimes help you spot obvious fakes. Keep in mind that toothpaste is mildly abrasive and can scratch softer gold or wear down thin plating, so avoid using it on delicate or sentimental pieces. Think of it as a quick home experiment, not a replacement for professional testing.

Why Does This Test Work?

This test works because toothpaste contains a small number of abrasive particles. When you rub the toothpaste onto the gold, these particles work to remove a thin layer of the metal.

The mild abrasives in toothpaste can react with base metals mixed into low-quality alloys, sometimes creating a dark residue on the surface. Higher-purity gold is less reactive and more resistant to this kind of discoloration. However, because different alloys behave differently, this reaction is not consistent enough to be treated as a definitive test.

Keep in mind that this test will not work on gold-plated items. The toothpaste will remove the thin layer of gold, revealing the metal beneath. So if you’re testing a gold-plated item, check for the hallmark stamp first. This stamp indicates that the item is made of real gold.

Now that you know how to test gold with toothpaste, you can at least get a first impression of whether your gold behaves like the real thing. For any piece with real financial or sentimental value, though, it is still worth getting a professional opinion.

Other Ways to Test Gold

There are a few different ways that you can test gold at home. But unlike the Toothpaste Test, you will need to invest in a gold testing kit, which you can purchase online or at most jewelry stores. With this kit, you can test the karat of your gold and determine if it is real. 

Here are a few different ways that you can test your gold:

Karat Test

When it comes to gold, the word “karat” is used to denote the purity of the metal. The higher the karat number, the purer the gold. For example, 24-karat gold is 100% pure, while 18-karat gold is 75% pure.

So how do you test the karat of your gold? Here’s a step-by-step guide:

1. Gather your materials. You will need a gold testing kit, which can be purchased at most jewelry stores.
2. Clean your gold. Use a soft cloth to wipe away any dirt or grime.
3. Place the gold on the test stone. The test stone is included in your gold testing kit.

Source: Dan Hurd

4. Apply the acid solution. The acid solution will react with the metal to determine its karat purity. Be sure to follow the instructions that come with your gold testing kit.

Source: Treasures and Adventures

5. Compare the results. The color of the acid solution will change based on the karat purity of your gold. A chart is included in your gold testing kit to help you determine the karat purity of your sample.

Now that you know how to test the karat purity of your gold, you can be sure that you’re getting what you paid for!

Magnet Test

Another way that you can test your gold is with a magnet. Here’s how:

1. First, obtain a strong magnet. A neodymium magnet is ideal for this purpose, but any powerful magnet will do.
2. Next, hold the piece of gold in question next to the magnet.
3. If the gold attracts the magnet, it is not real. Gold is not magnetic, so if it sticks to your magnet then it's probably made of some other metal.

Source: Arcadia Economics

4. On the other hand, if the gold is not attracted to the magnet, it simply means it is not obviously made of a strongly magnetic metal. Many fake gold alloys are also non-magnetic, so a “pass” on the magnet test does not prove that the piece is real gold.

So there you have it. A magnet test is a quick way to catch some obvious fakes, especially pieces that are clearly made with cheap magnetic metals. Just remember that passing the magnet test does not guarantee that a piece is genuine gold, so use it as one signal among many, not your only check.

Float Test

Yet another way to test your gold is with the float test. Here’s how it works:

1. First, fill a cup or bowl with water.
2. Next, drop your piece of gold into the water.
3. If the piece sinks to the bottom, its behavior is consistent with real gold, which is very dense. However, many other metals and alloys also sink, so this result on its own does not prove that the item is pure gold.

Source: LACONIC Jewellery

4. If the item floats or hovers strangely in the middle of the cup, that is a strong red flag that it is not solid gold and may be hollow, plated, or made of a much lighter material.

With the float test, you can quickly and easily screen for some obvious fakes, but you should not rely on it alone to determine whether your gold is genuine.

Final Thoughts

Gold is a valuable metal, so it is vital to ensure you are not being scammed. Simple at-home tests can help you spot some obvious fakes and give you a first impression, but they are not foolproof. Methods that use toothpaste, magnets, or water are best thought of as quick screening tools rather than final answers.

Whether you've just received a gold gift item or come into possession of a family heirloom, it makes sense to verify your gold if you are not 100% certain of its authenticity or origin. At-home checks with magnets, water, or basic test kits can be a helpful first step, but the most reliable results still come from proper gold testing kits and professional analysis at a reputable jewelry store or assay office.

When in doubt, always consult a professional. A trained jeweler will be able to quickly and easily assess the quality of your gold. Want to protect your gold investments from taxation and let your holdings accrue value over time? Check out our reviews of the best gold IRA companies in America.