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Don’t be fooled: Learn how to spot a real Diamond

by Willyou.net * Dec 24, 2021

Key Takeaways

  • While there are a number of diamond simulants out there, it is always possible to identify a real diamond from a fake.
  • There are a number of different diamond testers out there. Cheap, low-end testers will be easily fooled, but a jeweler with the right tools at their disposal won’t be.
  • Ultimately, the best ways to ensure that you are investing in a real diamond that is worth the money you spend on it is to shop from a reputable jeweler, who will have no interesting in duping you, to do your own research, and to ensure that the diamond in question is accompanied by a GIA or AGS report.
jeweler check diamond loupe - How to Tell if a Diamond is Real

It’s true that there is nothing quite like diamond, but there are a few gemstones, crystals and lab-grown synthetics that can be confused for diamond without closer inspection. You’ll want to avoid these at all costs, not only because they are nowhere near as valuable as diamond – both in terms of financial and cultural value – but because, despite some resemblance, they do tend to fall short in some way or another, even if it’s not clear straightaway.

It doesn’t take much insider knowledge to realize that there are plenty of pitfalls laid out for unsavvy shoppers, and that, without the right approach, you could be very vulnerable to investing in a low value dupe for true diamond.

But, how does the diamond world keep on top of this – and how can you be sure that you will, too?

What is the Fake Gem that Can be Mistaken for a Diamond?

Cubic zirconia, moissanite and white sapphire are all common dupes for diamond.

While each of these substances hold some pretty obvious visual similarities to diamond, their differences are relatively easy to spot if you hold a moderate amount of experience in diamonds, or gemology in general. For first-time shoppers, however, this is so rarely the case – and, while you know the basics of what a diamond should look and behave like, you probably don’t feel comfortable getting into specifics.

This is why some shoppers will end up fooled. It is, however, very important to note that a reputable local jeweler – one with a bricks-and-mortar business, rather than just a website – won’t be trying to pass off any other gemstone as diamond. No reputable business – whether a chain, independent store, or an online vendor – would risk their reputation by selling fake diamonds.

Nevertheless, as a practice, it’s much easier to get away with online, where shoppers can’t take a look at the stones in person or talk to an experienced jeweler first.

Are Uncertified Diamonds Fake?

Not necessarily, but you should never take a risk on a diamond that has not been formally graded by a reputable lab.

You can read our full guide to diamond certification here. At WillYou.Net, we only recommend our readers opt for diamonds that are accompanied by a GIA report – or, failing that, AGS certification.

Not all ungraded diamonds are fake, but no ungraded diamond is worth your time or, more importantly, your money.

Do Jewelers Sell Fake Diamonds?

A reputable jeweler will never sell a fake diamond under the claim that it is a real one.

Plenty of jewelers stock jewelry that features a wide range of other gemstones. While they’re nowhere near as popular for engagement rings, inexpensive alternatives like cubic zirconia are still popular for other types of jewelry, so it’s definitely not unusual for jewelers to have them on sale.

You are not going to ‘accidentally’ invest thousands of dollars into an inexpensive lookalike, however. The biggest risk comes if you are investing into a diamond online, and where you can’t ensure the trustworthiness of the vendor.

Can Diamond Testers be Fooled?

Some diamond testers can be ‘fooled’ by moissanite, which is why the most reliable option is always to get your diamond checked out by a jeweler. Their expert eye is often worth more than a cheap yester.

Knowing where to go to buy a genuine diamond is one thing – but what about older rings and family heirlooms you already have lying around the house? Sure, your grandmother insists that her old three-stone diamond ring is real, but how can you be sure?

So, How Do You Tell if a Diamond is Real Without a Tester?

The best way to ensure the authenticity of a diamond is to check that it is accompanied by a GIA report – and, if you’re unsure, to speak with your local jeweler.

There are plenty of at-home tests you can do. Most of them don’t provide definitive results on their own, but offer some pretty strong indications that your diamond is real. They can be split into two main categories – light performance and composition – and allow you to get up close and personal with the most distinctive features of diamond…

Light Performance

One of the most revered features of diamond is its unique light performance – but, at the same time, plenty of other gemstones sparkle, too. The differences may seem subtle at first but, once you are aware of them, you won’t be able to miss them…

Do Real Diamonds Sparkle in the Light?

Yes, real diamonds will create a very distinctive pattern of brilliance (white light) and fire (colored light) when hit by any natural or unnatural light source.

While you won’t be able to pick up on it straight away, there are some key differences between the way diamond sparkles and the way other stones like CZ and moissanite sparkle.

For instance, both cubic zirconia and moissanite produce significantly more fire, and a lot less brilliance. It might take a side by side comparison for you to recognize the difference at first, but it is possible.

How do You Tell if a Diamond is Real With a Flashlight?

While you won’t get any definitive results on your own, you can use a flashlight to create a as much sparkle as possible on the surface of your diamond, and judge those flashes of fire and brilliance for yourself.

In this experiment, the flashlight is merely a convenient light source used to generate as much sparkle as possible. It’ll work a lot better if you are able to compare your stone with a cubic zirconia or moissanite, and a real diamond, at the same time – but that’s probably not possible if you’re doing this from home.


Alongside sparkle, one of the features diamond is best known for is its strength and density – a result of its unique chemical composition. And, while it is possible for other substances to mimic the appearance of diamond, it is impossible for them to ‘copycat’ this composition.

Can You Scratch a Real Diamond?

Yes, although it’s not easy. Diamond is incredibly tough and durable, but it’s not impervious to damage.

Diamond scores the highest on the Mohs Scale of Hardness, but keep in mind that, with no special tools to hand, you probably won’t be able to differentiate between the hardness of diamond and the hardness of, say, a copper penny – despite the fact that they’re nowhere near each other on the scale.

So, yes, you can scratch a diamond – but, no, it’s not worth trying this just to work out if your diamond is real.

Can You Tell if a Diamond is Real by Scratching Glass?

A real diamond is hard enough to scratch glass, but you can’t be sure your stone is a diamond using this test alone, since there are plenty of other gemstones strong enough to do this.

Both moissanite and cubic zirconia will leave a scratch on your mirror, too, so don’t ruin a perfectly good piece of glass testing this.

Do Diamonds Float or Sink?

They sink, as a result of their high density.

Obviously, this test is a wasted effort if the stone in question is set within a ring – or any other piece of jewelry. But, if you happen to have a loose gemstone lying around, this can be a useful test, although it may not be definitive.

Can You See Straight Through Diamond?

Not clearly. While diamonds are transparent – with the exception of significant inclusions – you can’t look through them like a piece of glass, as they will distort any image on the other side.

If you place a diamond with the table (the flat, upper portion) against the page of a book, for instance, you won’t be able to read the words through it.

Are Real Diamonds Ever Set in 925 Silver?

Yes, although it’s not the most common choice for diamond.

If you own a ring with 925 engraved along the inside of the shank, then this is simply ‘jewelers’ code’ for sterling silver – a common and relatively inexpensive metal choice for everyday jewelry. It’s not particularly strong or durable, and can wear down with frequent use, so doesn’t tend to be chosen for engagement rings. Far more common, if your partner favors silver jewelry, is white gold or platinum.

Still, some diamonds are set within sterling silver, so a ring stamped ‘925’ isn’t necessarily housing a fake or lower quality gemstone.

Our Summary: Can You Be Sure Your Diamond is Real?

Whether you’ve yet to buy your diamond, or already own one that you’re not totally sure about, the bottom line is this: only an expert jeweler or gemologist will be able to give you the information you need to be 100% sure.

There’s a major difference in financial and cultural value – not to mention beauty and durability – between diamond and some of the more convincing alternatives. It’s totally understandable that so many people are preoccupied over the idea of investing thousands of dollars into something inauthentic.

The secret to avoiding this lies in research, but also in connecting with a genuine expert who can offer insight that takes decades to develop. If you’re still shopping around, then use our Jewelry Store Locator, which scours a database of stores across the country that have been extensively vetted by us in order to connect you with someone you can trust for this important purchase.

There will always be sellers looking to take advantage of the mystery surrounding buying a diamond, in order to sell something invaluable for thousands of dollars. That’s why we’re firm believers of the fact that removing the mystery from the process of buying a beautiful diamond is the most valuable thing you can do as a shopper.