How to Tell if a Diamond is Real? Spot a Fake With These Tell-Tale Signs

by | Apr 21, 2023 | Diamonds


Imagine yourself proposing to the love of your life. You spent so much time looking at rings, trying to secretly measure their ring size, saving money, preparing for the moment, memorizing what to say, and you know the rest.

You want everything to be perfect for her to say yes, and to live happily ever after.

How would you feel if, after you had the perfect proposal, you found out the diamond was fake? How would they feel? What would you do?

Let’s not dwell too long on these thoughts because we’re going to try to make sure you don’t end up with a fake diamond in the first place.

If you want the shortcut to not be in this situation, we encourage you to read Our Top Diamond Jewelry Retailer Comparison Guide, and then learn How to Buy Diamonds Like a Pro.

While most gemstone dealers are genuine and honest, there some unscrupulous ones who stock fake diamonds to rip customers off.

Don’t let that happen to you whether you’re buying a ring, earrings, bracelet, or any other piece of jewelry.

Here is a guide that will come in handy the next time you decide to visit the jewelry store.

Please remember one thing: Lab-created diamonds are not the same as fake diamonds, on the contrary, lab-grown diamonds are actually REAL diamonds.

How to spot a Fake Diamond Before Your Purchase?

Most people aren’t diamond experts but some tips and tricks will help you spot a fake diamond almost immediately. Be armed with a loupe, some sandpaper (probably won’t use it, but just in case), and a friendly face so the jeweler will be patient while you conduct your series of test.

1. The Loupe Test

A loupe is a small magnifier jeweler’s use that can magnify objects up to ten times their size. If you don’t have one, you can always politely ask the store to use theirs.

So what should you watch out for when observing the stone?

        • Firstly, make sure it has some imperfections in the carbon. Genuine diamonds are made by nature, and that means their carbons are slightly flawed. This does not take away from the stone’s value; it just ensures it was made naturally, this should be harder if you’re examining a high grade clarity diamond (VS and flawless)
        • Secondly, look at its edges. A genuine diamond will have sharp edges while a fake one will have rounded ones.
        • Finally, if you are buying a ring, check the metal that the diamond is mounted on. Generally all diamond rings are paired with gold or platinum bands, while fake diamonds are more likely to be mounted on steel or cheaper metals.

    2. Perform the Fog Test

    Try to create some fog on your diamond by breathing hot air on it. Think about how bathroom mirrors fog up with steam from the shower, or glasses become cloudy when leaning over a hot bowl of soup. This is the reaction you do not want. A real diamond won’t fog up because it doesn’t retain heat.

    3. The Refraction Test

    Diamonds usually sparkle for one reason – they refract light so intensely that you can’t see through them. To do this test, take your loose stone and place it on top of a newspaper or magazine.

    If you can still read the words below through the rock, then know you’re probably dealing with a fake.

    If the diamond in question is already mounted, and not loose, then make sure you can’t see the setting when you look through the diamond.

    4. The Sparkle Test

    As mentioned above, diamonds sparkle because they refract light intensely. But some fake diamonds sparkle too, so how can you tell whether yours is genuine? Well, start by holding it in light and observing how it sparkles.

    Inside the diamond, you should be able to see gray and white sparkles (referred to as “brilliance”). When the reflection hits an outside surface, it should form rainbow colors. Secondly, look at it under UV light. If it is a genuine stone, it should glow blue.

    Note that the amount of blue color depends on fluorescence grade, the color will be very limited if it has a grade of none.

    5. Rub it With Sandpaper (or at least, try)

    Chances are the jeweler will not allow you to do this, which makes sense, but if you can, try to rub the stone with sandpaper, please be very careful if diamond is mounted as you can easily scratch the ring!

    Diamonds are among the world’s hardest materials and can’t be scratched by rough surfaces. So, if you rub you see scratches after rubbing your stone with sandpaper know that you are dealing with a fake.

    How to Tell if Diamonds Are Real After The Purchase?

    If, for any reason, you didn’t have the chance to examine your diamond before you bought it, or if it was a gift from someone else, you can still check it out post-purchase.
    Use the following test to check for authenticity:

    1. Water Test

    Diamonds are very dense (3.5 compared to ~1 for water), and will always sink to the bottom when dropped into a water container. Other fakes like quartz will sink but slower that genuine diamond, note that other substances, like moissanite, also sink as quick as diamonds, so this test is not entirely 100% proof.

    2. Heat Test

    One outstanding feature of diamonds is that they are incredibly strong. They’re not affected by heat or cooling. Or at least not at the temperatures you and I can produce without the help of special machines.

    To perform this test, take your stone and heat it thoroughly for like 20-30 seconds, if it cracks or shatters, it is certainly not a diamond.

    If it doesn’t, then drop it in cold water. Again, if it neither cracks nor shatters then chances are you have yourself a genuine diamond.

    If It’s not a Diamond Then What it is ?

    Alright, you’ve done the test and you’ve discovered your rock isn’t a real diamond. What else could it be? There are almost half a dozen possibilities.

          • Moissanite: arguably the closest thing to a real diamond, this metal is hard and dazzles just like a diamond. The main difference is that its inner sparkle creates a rainbow rather than gray and white rays.
          • White sapphire: like diamonds, sapphires are used in jewelry. On the surface, the white type resembles diamonds a lot, only that it doesn’t have the same brilliance of a diamond. It is also prone to scratches.
          • White topaz: while topaz can usually be found mostly in yellow, brown, red, and pale gray colors, there is a rare white type that imitates diamonds.
            However, it is not a hard mineral and will wear down very quickly when compared to the strength of a diamond.
          • Cubic zirconium: this is a very popular crystalline form of zirconium dioxide that neither has the shine or strength of a diamond. However, it can trick you easily thanks to its high density and clarity. But its carbons are too perfect compared to those of genuine diamonds.
          • Artificial diamonds: technically speaking, lab-made diamonds are real, but of course they are not as valuable as natural diamonds. That is why they usually sell for up to 40% less than the real thing. If you want to tell whether a diamond is natural or lab-made, look at the perfectness of its carbon and the sharpness of its edges.

      With your newfound knowledge, you’ll be able to spot a fake diamond from across the room. Use these powers for yourself but try to resist bursting someone else’s bubble if you notice theirs is a fake. The best advice is always to buy your diamonds from a respected source, and even better, from one of the best large retailers online, like James Allen, Blue Nile, or the quality store Whiteflash.

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      About the author

      Olivia Bennett is a dynamic and accomplished expert in the diamond industry. With over a decade of experience, she has established herself as a go-to authority for all things diamonds. Olivia's love affair with these exquisite gemstones began in her childhood and has only grown stronger over the years.

      Having worked closely with diamond miners, manufacturers, and retailers, Olivia possesses a comprehensive understanding of every aspect of the industry. From diamond grading to sourcing and the latest design trends, her expertise is unparalleled. Clients value her impeccable taste, attention to detail, and personalized approach.

      Driven by a passion for education and empowerment, Olivia launched her own website dedicated to diamonds. Through engaging and informative content, she guides individuals through the intricacies of diamond buying, helping them make confident and informed decisions.

      Olivia's mission is to ensure that everyone finds their perfect diamond, one that truly reflects their unique desires. With her extensive knowledge and unwavering dedication, Olivia is a trusted guide in the dazzling world of diamonds.