How Can You Tell if a Diamond is Real? - Diamond Mansion Blog

How Can You Tell if a Diamond is Real?

How Can You Tell if a Diamond is Real?

Buying a diamond is a big purchase and there can be so many personal reasons why you’re doing so. Whether it’s love, commitment, a gift, commemoration, or something else, you need to know that the diamond you’re buying is real.

Many people are caught out by scammers who offer diamonds for a price that seems too good to be true – and unfortunately, that’s because it is. That’s why it’s especially important to be on the lookout for sellers who are trying to sell you fake diamonds, either online or in some cases, in person.

Diamonds Are Relatively Easy to Fake

It’s relatively easy to create convincing fake diamonds using artificial materials. The most common materials used are glass and cubic zirconia. It’s also possible to use synthetic rutile and strontium titanate, although neither of these have been in common use since the 1950s.

Other synthetic stones such as yttrium aluminum garnet, synthetic cubic zirconia, moissanite, and gadolinium gallium garnet are also used to create fake diamonds.

Any of these diamond substitutes can be convincing and look like real diamonds to the average consumer. Jewels made from these materials are easy and cheap to produce in the right conditions, which is why they’re so appealing to people hoping to profit from the inexperience of buyers.

However, when closely inspected, diamond substitutes have qualities – or lack thereof – that simply cannot be imitated. That means, when you know what to look out for, it’s possible to spot a fake diamond from a real one.

How are Real Diamonds Certified?

Certified diamonds are analyzed by experts and gemologists under laboratory conditions, whereby the diamond is tested to determine its quality.

There are several professional bodies where these tests and certifications are carried out.


The Gemological Institute of America (GIA) has been around since the 1930s and is one of the originators of the basic grading system that is still in use today. Today, GIA is the most trusted and renowned diamond grading entity. They are incredibly consistent and provide the greatest peace of mind when purchasing any diamond.

At Diamond Mansion, any stone larger that 0.50 carats in weight is accompanied by a GIA certificate.


The American Gem Society (AGS) was also established in the 1930s, and grade their diamonds from 0-10, with 0 being the highest quality and 10 being the lowest.


The International Gemological Institute (IGI) certifies diamonds worldwide, with a focus on Asia and Europe. As a result, they’re less frequently seen as a reliable source in the US.

Despite these and other bodies certifying the quality of real diamonds, some fakes do come with falsified certificates. That’s why it’s important to be vigilant when purchasing diamonds, particularly from unrecognized sources and sellers.

Diamonds are one of the most expensive and sought-after minerals, and so you need to be confident you’re buying the real deal, and not a cleverly disguised replica.

So, how can you tell if a diamond is real? There are several tests you can do at home yourself, even if you have no prior experience with precious stones.

How Can You Test Diamonds at Home to Identify Whether they’re Real or Fake?

Even though you may not be a trained gemologist, there are some simple steps you can take to ensure a diamond is real.

How do you tell if a diamond ring is real with a flashlight?

By holding a diamond close to a source of light, such as a flashlight, you can tell whether or not it’s real. Watch closely for the shimmers of light that shine from the stone. A real diamond will reflect light easily, and provide you with a disco ball or rainbow-like display. You can use a flashlight or lamp to do this and it will work best with white light rather than yellow.

If the stone absorbs the light, then there’s a chance that it’s a fake. Cubic zirconia and glass can produce an internal rainbow-like display of color, rather than a shine.

It’s worth noting that you shouldn’t base your decision on this test alone, and it should be done at the same time as other at-home tests.

Can you test whether a diamond is real using your breath?

This one sounds simple, but it can be effective. Simply hold the diamond to your mouth and exhale to produce fog, in a similar way you’d fog up a mirror. If there’s a visible layer of fog on the stone that slowly dissipates, then it may be fake.

Real diamonds don’t fog easily, so the fog will dissipate very quickly.

Can you use heat to identify a fake diamond?

This test can be tricky to do at home, so it’s only recommended if you have access to safe laboratory equipment, such as safety glasses, a beaker, and a Bunsen burner.

Simply heat the diamond in a flame for thirty to sixty seconds, then quickly drop it into cold water. With the shock of a sudden temperature change, a real diamond won’t be affected, however, a fake diamond will crack or shatter.

This test may not be something you want to do, as identifying a diamond as fake will destroy it. That means you shouldn’t try this method on any stone you want to keep intact and may have sentimental value.

If this is a test you attempt, make sure you take all the correct safety precautions to avoid potential injury.

Can you identify a real diamond using water?

Using cold water is a much simpler and safer way to test the validity of a diamond.

If you place the stone into water, a real diamond will sink to the bottom due to the density. Fake diamonds are far more likely to float or bobble around.

Can you use a magnifying glass to tell if a diamond is fake?

This is a much more difficult test to perform at home if you don’t have any experience or training in gemology. However, it may be possible to find slight imperfections within the stone, which mean it’s more likely to be real. Flawless diamonds are quite rare, and incredibly expensive, which means if you don’t spot any flaws then there’s a good chance the stone is a fake.

Can you use a black light to tell a fake diamond from a real one?

Not everyone has a black light at home, but if you do this can be a simple test to do.

Make sure the only light source is the black light and there are no other sources of light so it’s best to do this one when it’s dark outside. A majority of diamonds will shine blue under a blacklight, whereas fake stones may become yellow, white, gray, or green.

However, it’s worth noting that not all diamonds will shine blue. You shouldn’t rely on this method as your only way for identifying the validity of a diamond.

Can you scratch a diamond to test whether or not it’s real?

Performing a scratch test is a quick way of checking whether your diamond is real or a fake.

To do this, scrape the diamond across the surface of a mirror. If the mirror is damaged, then there’s a chance that the diamond is real. If the stone is damaged, then it’s likely a fake.

Not only does this test risk damaging your mirror, but it’s also important to note that some synthetic materials, such as cubic zirconia and moissanite, are also scratch-resistant.

How can you tell if a diamond ring is real?

If the diamond in your ring is real, then it will usually be set in a high-quality precious-metal ring, such as gold or platinum.

Check the inside of the ring for markings. 10K, 14K, and 18K will indicate the type of gold. PT and karat indicate platinum. Three digits, such as 770 or 900, indicate platinum or gold.

Other markings may indicate another metal, such as silver, was used. Sometimes, you may even see CZ, which indicates cubic zirconia. In instances like these, the diamond ring is likely fake.

Do Real Diamonds Sparkle?

As previously mentioned, yes, diamonds do sparkle. From inside, a high-quality diamond will sparkle white and gray, which is called “brilliance”. They can also produce rainbow-like light shows, known as “fire”.

Can You Tell the Difference Between Lab-Grown and Natural Earth-Mined Diamonds?

While there are ways of telling the difference between real and fake diamonds, it can be trickier to distinguish natural diamonds from lab-grown ones. In fact, everyday consumers will see no difference at all. High quality lab-grown diamonds contain the same chemicals and have the same physical and optical properties – meaning you’ll still see that sparkle and fire you’d expect with a natural diamond.

Of course, there is only a finite amount of diamond we can mine from the earth. That means lab-grown diamonds are more sustainable than natural ones, but aren’t valued as highly. Some time in the future, it’s likely more diamonds will be lab-grown, which will make natural diamonds all the more rare and valuable.

For more information, check out our blog post on six differences between lab-grown and real diamonds.

How The Experts Check if a Diamond is Real

Jewelers and gemologists use several tools and techniques to determine whether or not a diamond is real


A loupe is a small magnifying glass that can be held close to the eye and can help you see intricate details much clearer than with a standard magnifying glass. The expert will then check to see whether the stone has imperfections, which are the sign that the diamond is real.

Diamonds that are certified by GIA typically feature a micro-laser inscription of the GIA report number applied to the edge of the diamond (The girdle of the diamond).
The laser inscription is very small and can only be seen under a 10x+ magnification by trained eyes.

Diamond tester

Another common way experts check the validity of a diamond is by using a diamond tester. This is a small electronic device that emits light and sound, alerting the expert as to whether or not the diamond is real.

High profile weighing

Jewelers and gemologists have access to finely-tuned scales that can detect minute differences in weight, and are far more accurate than the average scale you may use at home. Real diamonds tend to weigh less than their fake counterparts.

Give the gift of diamonds

At Diamond Mansion, we pride ourselves in only providing the highest quality natural earth mined diamonds. Browse our collection of diamond engagement rings.