How to know if a Diamond is real or not?

real or fake diamonds

Whether you are planning to propose to your girlfriend with a diamond engagement ring or want to give your mom a beautiful diamond pendant on her birthday, it’s important to know you are buying the real diamond. Every woman is fond of diamonds and nothing can make them happier than a diamond jewelry gift. Also, nothing can be worse for them than a diamond turns out to be fake. Hence, it’s important to know that the diamond you are buying is real or not.

Not only a gemologist would or should know how to detect a diamond, but it’s equally important for every buyer. Because there are many con artists there who try to sell out a piece of glass or plastic claiming it’s a diamond. If you don’t want to get cheated or be fooled by such jewelers then you must know how to check if the diamond is real.

And if you have already bought a diamond ring or any jewelry, or you have just discovered that your granny has left a few loose diamonds, but you want to be sure that they are diamonds. Then you can do the following things to test the stone.


One of the best quickest ways to know whether your diamond is real or fake is to try fogging it up with your breath. If the fog clears up just after one or two seconds then it means your diamond is real, but if it stays for more than that then chances are that you are having or holding a fake diamond.

This happens because diamonds disperse the heat instantly making it impossible to fog up while the non-diamonds have not the same quality so you will not see the same effect on them. But, before doing this test, make sure the diamond is neat and clean and no oils or coating is covering the stone. Only then this trick is going to work.

For this you can use the stone you know is real and the suspect stone and fog both. You will see that the fake one will fog up easily for a couple of seconds. If you will breathe on the fake diamond repeatedly, you will see condensation start to build up. The real diamond will stay clean and the fake will fog up more and more with each puff.


Use the simple water test to know you have a real diamond. Just fill a glass with water and drop the stone into the glass.

Diamonds are incredibly dense, so it will neither float on the top of the glass nor sink to the middle, but it will sink to the bottom. If your stone is floating on the top or sinks to the middle then it’s a fake diamond.

But, you must know that the cubic zirconia and glass that are fine cut and are pretty heavy can pass this test. So, the water test or density test is not foolproof.

Related Article: Understanding the 4C's of Diamonds


Fake diamonds will never be mounted or set in cheap metals. So, you should check the stamps to know whether the metal is real gold or platinum. Stamps inside the setting indicate the real gold or platinum and the signs like 10K, 14K, PT, Plat, etc. are the good signs. While the sign of ‘C.Z.’ indicates that the center stone is not a real diamond. C.Z. means Cubic Zirconia which is a synthetic stone and a good diamond alternative.


You can use a jeweler’s loupe to check the imperfection of the stone to know whether you are holding a real or fake diamond. Mined diamonds have minor imperfections, which are called ‘inclusions’. These inclusions can be seen with a loupe. You can borrow it from any local jewelry shop.

Though the natural diamonds look flawless under a magnifying glass their imperfections can be spotted because they naturally occurred so they have small imperfections. But, the lab-grown diamonds will be clear and flawless when seeing through a magnifying glass. And if you find it difficult then you can bring the diamonds to an expert for close examination.

Related Article: Everything You Need to Know About Lab Grown Diamonds | Lab Created Diamonds


It’s also one of the easiest and best ways to tell if the diamond is real. For the test, you will need a newspaper and a loose diamond. Put the diamond with the pavilion facing up, on a section of text in a newspaper. Now, try to read the texts through the stone. If you can easily read through the stone then it’s a fake and not a real diamond. But, if you can’t read through or the texts are blurry then this is a good indication of having a real diamond.


Fake diamonds are rounded and have dull edges because these are made by melting the glass or Zircon in a mold. But, the real diamond edges are sharp and exact because they are cut by professional cutters.


One of the strongest substances on earth is diamond. Though they are hard enough to cut glass some other gemstones can also scratch the glass. So, something like a scratch test that could help you to know if the diamond is real or not can be a bit tough.

But, you can still go for the test using glass and loose diamond. Place the glass on a table and start scratching the glass’ surface with the stone. If it scratches the glass then chances are good your diamonds are real. This can also damage the diamond. This won’t be the most effective way to see if your diamonds are real or not, because other synthetic gemstones can have the same effect on the glass.


This test should be only opted for when you are ready to take risk of damaging the stone. Because the diamonds can stand the heat and if the diamond is inauthentic it can extreme heat may damage the stone. You should only follow this test if you are ready to ruin your stone if it will prove wrong or false.

You can use a lighter to heat the stone for at least 30 seconds before putting it in cold water. Diamonds are stable materials and drastic temperature changes will not affect their natural integrity. So, when you will heat the diamond and quickly drop it in the water, it will simply sink to the bottom of the glass. It wouldn’t be affected by the drastic temperature changes from hot to cold. And the fake will shatter immediately.


If you don’t have the newspaper for the test then ‘the dot test’ is the best alternative.

Place a white or blank paper on a table and make a dot on it with a pen. Then place the diamond over the dot with the plain or flat side down. Then through the pointed end of the diamond look down on the paper. If you could see a reflection of a circle through the stone then it’s a fake diamond. If you can’t see the dot then it’s a real diamond.

Real diamonds have refractive qualities, the light reflects in various directions instead of a straight line. And this is the reason why you cannot read or see through a natural, real diamond.


This may not be possible for everyone to weigh or scale a diamond at home. So, you can go to a local jeweler, who can weigh the diamond for you easily. If the gemstone will weigh more than a diamond of the same size and shape then the stone is not a real diamond. It’s probably the Cubic Zirconia the synthetized gemstone that weighs approximately 55% more than an actual diamond. To perform this test, it’s important to have two stones of the same shape and size and most important the real one.


When the diamonds are placed underneath the ultraviolet light (also known as black light) it glows blue. Sometimes you will also see the color reflection of yellow, white, green, and red, but blue is the most common fluorescent color in the diamond. The fake ones on the other hand don’t look blue under the blacklight or UV light. But, this test is not most the reliable test to know about the authenticity of your diamond.

For this, you can contact a jeweler or visit a nearby diamond store. There an evaluator or appraiser will evaluate the stone for you using specialized equipment and will let you know whether the diamond is real or not. Always remember to get a certificate or grading report when buying a diamond or diamond jewelry.