A Guide On How To Spot Fake Diamonds

Written by
Ruby Buddemeyer
Need to have your item authenticated by EXPERTS?
Get help NOW
100,000+ customers
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

Last Updated on June 28, 2022 by Ch David

Pretty as they are, purchasing diamonds requires a lot of thought. From the budget to purchasing an authentic piece, there’s just so much to worry about.

However, when it comes to finding the right one, you’d need to consider few things and know of certain tricks to tell which stone is truly a diamond. 

If you are questioning your gemstone, you can always get it checked on LegitCheck By Ch and get a Certificate of Authenticity. But before that, you can try a few tricks by yourself as well. 

Scratch Test: Yeah or Nah?

One of the easiest and the most common tests to check for fake stones is the ‘scratch it to see’ test. Technically, if a stone can scratch a mirror, then it is probably a real diamond.

However, the primary thing to remember in this aspect is that the reason behind the scratch test’s authenticity was because the diamond was supposedly harder than a mirror, so it would leave a scratch.

As per Mohs Scale, the scratch test is more or less inaccurate. The scale suggests that mirrors are rated at 5.5. The same scale says that diamond is a 10, which means moissanite, which is 9.25, or quartz, which is 7, could also scratch a mirror.

That said, a scratch test probably won’t help you find out if it is an authentic diamond or not. Most synthetic diamonds would have authentic properties to make them look like the real ones. 

That being said, a lot of times people confuse lab-grown diamonds to be fake and different from earth-grown ones. That is not the case. Lab-manufactured diamonds are similar in authenticity to earth-grown diamonds, but it eliminates the environmental concerns, making them more ethical and conflict-free diamonds

However, real diamonds are always worth the money compared to ones made of moissanite and other equally hardened elements.  

How to Spot a Fake Diamond?

An authentic diamond would have many properties that fakes will not. Some things should be remembered or known about true diamonds. There are some tells that help in creating the perfect guidance for you to know if the stone is worth it or not.

If you are looking for ways to tell if a diamond is real or not, then here are some ways to help figure out if the stone you have is a real diamond or it is fake:

The Magnification Test

Photo from Wikimedia Commons

First, you would have to use a microscope to test the diamond you find questionable. Next, you’d have to compare it to your real diamond – one that comes with a certification and is quite affirmatively authentic. Next, you would need to run the diamond under a magnifying glass with 10x magnification. 

If you see certain flaws or ridges in the diamond, then you have the real deal. The thing is synthetic diamonds are created in labs, which is why those diamonds do not go through the natural process. Natural diamonds have some internal or external flaws, which are known as inclusions.

Compare the two to understand the difference, and use your understanding for all future tests. However, not everyone who owns a diamond is an expert in understanding the difference in composition. For them the following tests are more useful. 

The Water Test

Photo from Pixabay

Water testing a diamond is simple. All you’d need is glass and some water. Fill 3/4th of the glass with water, then drop the diamond in the glass. Real diamonds completely get immersed and would settle at the bottom of the glass because of their high density. 

However, a fake diamond would not. It would either stay afloat or would not sink all the way and would stay floating somewhere above the bottom.

The Hot and Cold Test

Photo by David Tomaseti on Unsplash

An excellent way to see if you have authentic or fake diamonds is to test them by heating. All you would need to do is heath the diamond or the stone for approximately forty seconds with a lighter. Use gloves or forceps to do so. Once heated, drop the heated diamond, without waiting for a second more, into a glass of cold water. 

Any rock that is not as strong as a diamond would shatter at impact or develop a black layer of soot on top. Diamonds can withstand heat and change in temperatures. However, any other stone would not. 

If the rock does not crack or shatter, then your diamond piece is probably the real deal.

You can conduct both the water test and the hot and cold test together. 

The Fog Test

Photo by Sabrinna Ringquist on Unsplash

Fog tests are simple and don’t require much knowledge about diamonds. Bring the questionable diamond to your mouth and puff air on it. If the diamond stays fogged because of the vapour for a few seconds, then it is possibly fake.

Since diamonds are excellent conductors of heat, the heat is dispersed quickly. However, fake diamonds do not have the same property, which is why they stay fogged up for some time. 

The Dot Test

Photo from Pixabay

The dot test is an excellent test to check the diamond’s refractivity. All you’d need to do is create a single dot on a piece of white paper. Place the diamond with its flat side down, and see if you view the dot on the paper. 

If you can, then sadly, the diamond is fake, even if the reflection is blurry. 

A true diamond has great refractive properties with an index of 2.417, which means that when light enters the diamond, it bounces off in several different directions. Meaning, a real diamond would not let you see a dot or any letters through it.

The Black Light Test 

Photo from Wikimedia Commons

All you need is a black light to test a diamond. Turn off all the lights and hold the diamond in front of the black light. If the diamond gives gray, yellow, or slight green fluorescence, then your diamond is fake. True diamonds give off a strong blue fluorescence.

What to do when you have a diamond to test? 

  • First things first, if you have no equipment or knowledge of diamonds, it is best to get it checked through an experienced jeweler.
  • If you have trouble believing which is true and which is not, choosing a certified diamond will allow you to bypass all of these issues.

With that said, it is always easy to find out which is an authentic diamond through many tests. However, it must be remembered that tests won’t do you any good if you do not know what to look for. With the above methods, you’d have an idea of what a true diamond should look like. Even so, it would not hurt you to get some expert opinion.

80+ Safest Places to Buy Items Online From

Want to avoid scams for your next sneaker, watch, designer item or bag? Enter your email address and we'll send the FREE guide over.
Hey! Thanks for telling us that! We'll keep you updated!
Oops! Something went wrong while submitting the form.

About the Author

Ruby is the beauty editor at Cosmopolitan, where she covers beauty across print and digital. Her work has appeared on The Zoe Report, Fashionista, The Oprah Magazine and StyleCaster.
Read more about the Author →