How to Tell if Your Diamonds Are Real: Pt.1

Jul 24, 2018 | Alternative Investments, colored diamonds, Diamonds

Diamonds, be it colorless or colored, are all assets to be admired. They are so rare, mesmerizing, and breathtaking that we often spend thousands or even millions to acquire them. The question is, how do we know that the asset we invested our money in is genuine? (Assuming we don’t have a certification.)

diamond real testSource

In this 2 part series, we will be going over how to assess if a diamond is truly natural, or a synthetic “impostor.” 

So how can you test if your diamonds are real or fake from the comfort of your own home?


Will it Sink or Swim?

Real diamonds have really high density and are solid on the inside, meaning if placed in water they will sink all the way to the bottom. To test your stone, take an ordinary glass of water and fill it to around 3/4. Now all you need to do is place the stone in the glass. A fake gem will float, sink lightly, or even float slightly underneath the surface. On the other hand, a real diamond will sink like a rock.

Breath Test

Real diamonds are excellent conductors of heat, this means that they can disperse heat very quickly. Knowing this; lift your diamond with a pair of tweezers (if it is loose, if not just hold the ring or piece of jewelry with your fingers) and gently breathe on the stone. If the fog takes a few seconds to disperse, then the gem is likely fake, conversely, if the fog gets dispersed almost immediately then the diamond is real.

breath test diamondSource


Setting Test

This test only applies to diamonds that have been set in a piece of jewelry (most commonly a ring.) 

Due to their high value, diamonds are usually set in high-quality jewelry such as platinum, gold, and white gold. In order to check if the stone’s setting is truly of such quality, check the inside of the ring’s center for a descriptive engagement.

  • 10K, 14K, and 18K all are indicators of quality of gold
  • PT and Plat refer to platinum
  • Numbers including 585, 770, 900, and 950 can also indicate quality for either gold or platinum

However, if C.Z. is present, the gem is actually cubic zirconium and not a real diamond.


Will it Break Under Intense Heat?

Diamonds are formed under instances of intense heat and massive pressure. It is because of this that their molecular structure is extremely strong and resilient.

If the stone is loose, pick it up with pliers or metallic tweezers (for your own safety you might want to do this wearing gloves and preferably outside) and heat the gem over a flame for about a minute. Then quickly drop the stone into a glass or container with cold water. If the stone fractures or shatters because of the quick and drastic change of temperature, it is not a real diamond.


Use Refractivity

Diamonds, especially colorless ones, are known for their ability to excellently and beautifully refract light, this is known as brilliance.

Shine a light on to your stone and pay close attention to how the light enters through the gem’s pavilions (located on the lower half), and how it is refracted throughout the body and its table (the flat surface of the diamond on the top.) The intense sparkle, pattern, and beauty are almost impossible to mimic in anything other than a truly natural diamond.

Other types of gems such as cubic zirconium, do not have the ability to refract light as well (if at all.)


The Newspaper Test

This is a simple one; all you have to do is take the gem (assuming it is loose) and place it onto a page of a newspaper (or any other book, magazine, even an electrical bill, or bank statement, as long as the letters are small enough to fit under the stone) with its flat side down. Next, make sure that there is plenty of light and that nothing is casting a shadow on the stone. If you are able to read the letters below, the gem is not a real diamond.

real vs fake diamondSource

Like we said before, real diamonds refract light in multiple different directions, this would cause the letters below the diamond look distorted and illegible.


Use Reflectivity

The reflectivity of diamonds includes:

  • Brilliance: White light sparkle
  • Fire: Colored light

Here you don’t need anything intricate, just a source of light. Hold the gem under a normal lamp in your home and pay attention to how the light is reflected off the stone. Real diamonds reflect both types of light extremely well and in magnificent patterns, no other substance can replicate.


The UV Test

To test a diamond in a different way, place it under a UV light and watch the reaction. Most diamonds will emit a blue colored glow, but not all of them. Some diamonds do not glow under UV light. For this reason, if the stone does not glow, the results don’t necessarily indicate that it’s a fake diamond.

uv light

Because this test is not definitive, it’s best to have a diamond expert or jeweler use their advanced equipment to test the stone.

And there you have it. Now note that while this guide is useful and practical, no single at-home test should be regarded as conclusive. A diamond expert has the proper experience and equipment to confirm if a diamond is real or fake.

Next time we will go over the various tests that a gemologist performs on a stone to see if it is a true diamond or some sort of “impostor.”

Did you have any questions? Is there something you want us to add more detail to? Let us know! And as always feel free to follow us on Twitter and LinkedIn.

To read more about the most famous colored diamonds in the world, see the link below:

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