diamond tests

Diamonds are precious, rare, and expensive. Buying one can be a heavy purchase for most people. Surely, you won’t want to handle this investment wrongly.

Hence, before picking out that special stone for that special someone, you should know how to tell if a mounted diamond is real or not. Many gems greatly resemble diamonds. A few include white sapphire, topaz, and white zircon.

12 Ways to Tell If A Diamond Is Real 1

With that in mind, you need to have some knowledge to tell a real Diamond from one that mimics it. If you’re already in possession of a diamond ring and doubt its authenticity, see a professional jeweler. But if you don’t want to, there are a few tests you could run at home to ensure your stone’s genuineness.

Ways on How to Tell If A Diamond Is Real

How can you tell if a diamond is real or fake? You can put your gem through one or more of these tests to find out its quality.

1. Test by Scratching

This test is based on the fact that Diamonds are one of the strongest substances on the planet, making them cut through glass. This is the scratch test, and it should prove that your glass is real, or not. All you need is a plate of glass and your diamond in hand.

Set the glass on a platform, then scratch its surface using your diamond. If you get a scratch, there’s a good chance your diamond is legit. If you don’t, then it is fake.

However, it should be noted that this process could also damage the glass. It is also not one of the most effective tests for your stone’s quality too because many other gems could replicate these results.

2. Test by Fogging

A quick and easy way on how to tell a real diamond from a fake is by fogging it with your breath. It should clear up after a second or two, proving your diamond is real. If it stays fogged up for three, four seconds, then you’re probably holding a fake.

Diamonds instantly disperse heat, making it impossible to remain fogged. However, none diamonds don’t have a similar effect.

To perform this test, ensure your diamond is clean and free of oil stains and coverings. If you have a real diamond with your suspect stone, perform the test on both.

Observe how the real one remains clear, while the fake fogs over the as you breathe in it. The phony stone fogs up more and more, building condensation, while the real diamond remains clean and clear.

3. Float/Water Test

FloatWater Test

This test stands out as one of the easiest tests, albeit non-conclusive. It is because the density of diamonds is very high. To perform this test, you need a glass of water and a diamond.

Drop your diamond in the glass of water. If it is real, it will sink to the bottom. If it is fake, it will float on the water surface.

Keep in mind that not all fake diamonds float in water. Hence, you may have to perform further tests to know if it real or not.

4. Test by Heating

Diamonds are unresponsive to heat due to their incredibly strong material build. This method is also known as the heat test. You need a glass of cold water, a set of players or fireproof gloves, and a lighter to perform this test.

Heat the stone for about 40 seconds and immediately drop it directly into the cold water. If the stone breaks, it means that the diamond is fake because real ones would show no reaction.  This method shows the strength and quality of the stone.

Weaker materials or gem such as zirconium crack due to continuous quick expansion and contraction caused by the heat. Consider Pyrex dish when cooking for example. If you try to wash it immediately after pulling it out of a hot oven, the dish may shatter due to a shock in temperature change.

Diamonds being one of the strongest materials on earth, gives them resistance to such extreme heats. They can disperse heat quickly, so a change of temperature does little to affect them.

5. Transparency Test

Transparency Test
Image: something borrowed

For this test to work, you need a newspaper and your diamond to be very clean. Place your diamond face down, with the pavilion facing up, in a section of the newspaper.

If you can read the letter through the diamond, then your diamond is probably fake. If the letters are blurry, this suggests that you have a real diamond.  

6. The Dot Test

This method is an alternative to the Transparency test, but with regular white paper. Place your piece of paper on a flat surface and use a pen to draw a small on it. Then lay your diamond onto the dot, with the flat side down.

Look down onto the paper through the pointed end of the diamond. If you’re able to see a reflection of the circle inside the stone, it means it is fake. If you’re unable to see the reflection in the stone, that means you have a real diamond.

Diamond has great refractive qualities. Light bounces through it in different directions, instead of a straight line. Thus, you can never read letters or see dots through a natural, real diamond.

7. Test the Sparkles

Perhaps all you have on you at that moment is your smartphone and your diamond. If your phone has a torch, you’re fine. You’re probably wondering how to tell if a diamond ring is real with a flashlight.

It’s simple as all you need for this quick and easy test are your eyes. You should also know that a diamond reflects light excellently, giving out powerful sparkles. All you need to do is hold up your diamond to a regular lamp and observe the sparkles and shimmers brightly.

Additionally, diamonds make beautiful displays with their reflection of fire and colored light. Unlike other stones such as Cubic Zirconia, you’ll notice the huge gap in the difference between their reflection to colored light. Cubic Zirconia produces notable rainbow-colored light.

However, keep in mind that you may have to perform other testing methods as this isn’t a full-proof procedure.

8. Inspection Under Ultraviolet (UV) Light

Inspection Under Ultraviolet (UV) Light
Image: something borrowed

Most, not all, diamonds display blue fluorescence when exposed to ultraviolet or black light. This diamond lighter tester confirms that your diamond is real.

However, it might not exhibit exactly the blue light. Not all diamonds fluorescent under UV light. A slight fluorescence of green, gray, or yellow light may suggest the stone is moissanite. UV tests go only as far as narrowing down your choices of possibilities.

I wouldn’t recommend using this test as the only and final determinant. Other than the chance of dismissing real diamonds as fakes, you could also take fake diamonds as the real thing. This is due to a process called Doping.

Diamonds are treated so they glow under UV light, when, naturally, they cannot. The sun emits UV rays in massive amounts, so you can also check for a real diamond in sunlight and observe the reaction.

9. The Magnifying Glass Test

Most real diamonds have certain imperfections, referred to as inclusions. Hold up a magnifying glass to your diamond and observe it through the glass. Then look closely to find these imperfections.

If you find none, then your diamond is probably fake. Of course, there are diamonds without imperfections, but they are either lab created or too expensive.

10. Use A Loupe to Check the Diamond

You could say a Loupe is to Jewelers, what a stethoscope is to Doctors. Like a magnifying glass, Loupes are used to observe a precious stone’s tiny details closely. The differences between the Loupe and a magnifying glass are the lack of handles and the more conical lens frame.

Most Jewelers use loupes to inspect diamonds for clarity and class. If you don’t have one, there is a large selection of Loupes on Amazon to choose from at a reasonable price. Once you’ve got one, you can begin your stone inspection.

The first thing to look out for is tiny imperfections, which mined diamonds usually have. Secondly, check for slight color changes or small flecks. If there are, then you most likely possess a real diamond.

It should once again be noted that there are Perfect Diamonds, ones without any flaws. So if you observe none of the flaws, it shouldn’t necessarily mean you’re holding a fake diamond. It could mean you possess a rare perfect diamond, and thus, your stone is worth much more.

Most real diamonds indeed possess imperfections, but I still wouldn’t suggest using this as your only determination. Take lab-created diamonds, for example. Due to the controlled environment, they’re made in, it is easier to find no flaws.

It might be challenging to locate any flaws. Unless you have some experience in checking diamonds, you might find it a little difficult to spot inclusions on them.

11. Make Use of a Diamond Tester

Other than using a Loupe, most gemologists possess a thermal conductivity probe or meter. This tool is used to determine the thermal conductivity of a gemstone. The diamond should disperse heat rapidly after when it is warm, due to their heat conducting properties. disperses

Most synthetic moissanite stones usually have similar or identical way it disperses heat as real diamonds. Thus, this test is inconclusive with moissanite.

There are many available real diamond testers on the market, so feel free to select your favorite. You can get a look at an example from Amazon on the right.

12. Scale Your Stone

You should know that the tools used in scaling a diamond aren’t a common household item. Hence, it is advisable to take it your local diamond jeweler, so they can get it weighed for you.

You’ll know if the stone is a fake if it weighs more than and actual diamond of the same size and shape. The reason is that Zirconia, which is a synthesized material, weighs about 55% more than a real diamond.

If your diamond is certified or has a grading report, you can match it to the weight recorded. To perform this test properly, you will need two stones of the same shape and size, one of which you know is real.


Now, with all the information provided, you can ensure your diamond is the real deal. So, I am certain you know how to tell if a diamond earring is real, be it a diamond watch or a diamond necklace.

From simple home tests to advanced full-proof methods, you can decide how you want to go about it. I suggest you pick out about three of these tests, if you’re doing it on your own, or take your rock down to certified jewelry. So, get up now, and put your diamond to the test!

12 Ways to Tell If A Diamond Is Real 2

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