How to Test Real Diamonds?

Receiving or buying a diamond is an emotional purchase. Whether it’s your precious engagement ring or a necklace, diamonds are the weakness of many. How not love them if they make us light up every room. But not all diamonds are real, especially now that a lot of brands are promoting lab created diamonds, you might wonder how to check real diamonds at home.

Whether the jewel you want to test was given to you or inherited, it is very easy to do a few tests to find out if the stone you have is real. Of course, the best option is to seek advice from a reputable jeweler. However, you may be wondering, how do you test a diamond yourself? Well, we have the answer for you and we’ve put together — The top 5 simple tests to you can use at home to tell if a diamond is real or fake.

1 - THE VISUAL INSPECTION TEST

Mine diamonds typically have small natural inclusions, which are large crystals formed within the stone affecting the internal composition. We will also find blemishes that occur after a diamond’s formation, during the cutting, mounting, and polishing process.

For this test we recommend using a jeweler’s magnifying loupe to facilitate the overall inspection. We will be looking for small mineral flecks and very subtle changes of color, which are signs that your diamond is real, as well as inspecting the color of the sparkles.

Ensure to set the right environment to perform the inspection. Clean your jewel and it’s best practice to hold the jewel using a cloth, glove or tweezers.

Things to keep in mind:

Lab-made diamonds and cubic zirconia are generally free of blemishes. That’s because they are created in highly controlled environments instead of being a product of nature. Usually, a diamond that is too perfect turns out to be just a fake.
The sparkles, the way a real diamond reflects light is unique, the inside of the diamond should sparkle gray and white, while the outside should reflect a slight rainbow of colors onto the surface. A fake diamond will have rainbow colors on the inside and the outside.
Note that cubic zirconia has an orange-like tone of sparkles, while lab diamonds reflect a blueish shimmer.

2 - THE WATER TEST (ONLY FOR LOOSE DIAMONDS)

This test is perfect if you have a loose diamond. You will only need a glass of water. You may be wondering, are real diamonds heavier than fake? The answer is yes.

See, due to the high density of real diamonds, when dropped into the water a real diamond will sink while a fake one will float to the middle or top of the glass. Note that lab-grown diamonds have the same density as real diamonds, so this test will only work for other types of fake diamonds.

3 - THE FAMOUS FOG TEST

This test has been practiced since the beginning of the diamond industry. It is recommended first to try the test with a real diamond, this will allow you to fully grasp the difference. A real diamond won’t fog easily since the condensation doesn’t stick to the surface, you might see a slight flog but it will evaporate rather quickly, on the other hand, fake diamonds will easily fog and the evaporation process will be longer. You will observe how the real diamond stays clean and the fake one stays tarnished.

How to perform the fog test? Very easily, gently grab your jewel then place it at the height of your month and with an open mouth exhale towards your jewel. With each breath, a fake stone would fog more and more while a real diamond would remain clean and clear.

4 - THE FIRE TEST

Have you heard the saying “diamonds are forever”? Well, it’s true, because they are incredibly durable, see, durability in a diamond is the ability to withstand wear, heat, and chemicals. A real diamond has the necessary resistance to extreme temperatures which is why it is one of the strongest materials on earth, so don’t worry it will remain unaffected. Whereas, a fake diamond will shatter. This test is best recommended for loose diamonds.

To conduct this test safely we recommend wearing glasses to protect your eyes and a pair of pliers or tweezers. Note, this test is very simple, nothing will explode, but ensure to perform it in the kitchen or bathroom, or any place where you can quickly control fire.

Tools needed:

Pair of pliers/tweezers
Lighter
Glass of cold water
Protective eyewear

To perform this test, hold the diamond with the plier and switch the lighter on. Hold the fire directly to the stone for 35 seconds, then drop the stone into the glass of cold water.

Rapid expansions and contraction will crush the tensile strength of weaker materials such as glass, quartz, and cubic zirconia, causing the stone to crack from within. If you are holding a real diamond, nothing will happen.

5 - DIAMOND TESTER (THERMAL CONDUCTIVITY PROBE)

Yes, you can easily purchase a diamond tester online. This device will allow you to test your stone’s conductivity which determines whether it is a real or fake diamond. Please note, lab-grown diamonds will provide the same result as real diamonds, so this method will only discard other types of fake diamonds.

How to use a diamond tester:

Step 1- Clean your jewel
Step 2- Gently remove the protective cap from the tester tip
Step 3- Hold the tester in your right hand with your index finger touching the electricity- conducting panel on the top of the tester
Step 4- Press the probe tip at a right angle (see example) onto the top of the stone. Do not press the tester to a stone at an angle less than 90 degrees.

Notes:

Too much force may break or bend the probe tip! Do it gently.
When testing stones that are already mounted, hold settings with your left hand.
For loose stones, best results occur when the stone is placed in the testing base.

The interpretation of the test results will be granted by the tester that you purchase.

NOW LET'S DIVE INTO POPULAR Q&A

How Can You Tell If A Diamond Is Real With A Flashlight?

Yes, you can use a flashlight or even better the sunshine, basically, the main point is to do a sparkle inspection, as mentioned above real and fake diamonds shine differently, and this is one of the easiest ways to differentiate them.

How Can You Tell If A Diamond Is Real Without A Diamond Tester?

Certainly, if you know what to look for, then you can definitely spot a real diamond from a fake one.

What Does A Real Diamond Look Like? And Does A Real Diamond Sparkle A Rainbow?

Real diamonds will look unique depending on the carat, color, clarity, and cut. But there is one main factor that truly determines whether you have a real or fake diamond and is the sparkle. As previously mentioned the way a real diamond reflects light is unique, the inside of the diamond should sparkle gray and white, while the outside should reflect a slight rainbow of colors onto the surface. A fake diamond will have rainbow colors on the inside and the outside.

Is My Diamond Real If It Sinks?

Yes, if you perform the water test and your stone sinks, you have a real diamond!

Do Fake Diamonds Shine In The Dark?

In general, neither real nor fake diamonds shine in the dark, unless you have a diamond that belongs to a group called type IIB which is extremely rare. These diamonds are often blue or gray in color, after they absorb high levels of UV light they will glow in the dark for a short period of time.

Are Real Diamonds Heavier Than Fake?

Real diamonds are significantly heavier than any fake stone, this is due to the density of the diamond.

Do Diamonds Shine Underwater?

Diamonds shine because they reflect light, if you are underwater and there is light your diamond will certainly shine, of course, way less than outside the water.

The Recap

We looked into all 5 tips to check real diamonds at home. Now you may be wondering which one to do, find below a list of recommendations:

1 – THE VISUAL INSPECTION TEST: This test is highly recommended at all times and with any type of diamond.

2 – THE WATER TEST (ONLY FOR SINGLE, LOOSE DIAMONDS): As labeled, the water test only works for loose diamonds.

3 – THE FOG TEST: This simple test works wonders but the diamond needs to be faily big to be able to view the condensation forming. Pavé diamonds will not work with this test.

4 – THE FIRE TEST: This is the fastest way to test a loose diamond.

5 – DIAMOND TESTER (THERMAL CONDUCTIVITY PROBE): This is the most effective way to test a diamond at home.

We are happy to share these 5 effective ways to test diamonds at home. However, the best way to make sure that your jewelry is made of real diamonds is to purchase from trusted and professional jewelry stores. Here at Manuela Mejia Jewelry, we work with the finest diamonds and precious stones, quality without compromise and we offer concierge-level service for both our online and custom orders.