How to Tell if a Diamond is Real/ April 2024


It has long been the eternal struggle and question of many a consumer: “Is my diamond real?” 

To save you the heartache, headache, and hassle, we have put together this definitive Diamocycle Guide on how to tell if your diamond is real or fake. While the internet is full of myths and ways to determine if your loose diamond or diamond jewelry is real or fake at home, we’ve put together this resource that not only dispels the false myths surrounding how to tell if your diamond is real or fake but also offers real tips for ways you can determine the authenticity of your diamond. 

That said, please note, above all, we recommend bringing your loose diamond or diamond jewelry to a gemologist to obtain a GIA diamond certificate form to tell you whether your diamond is real. A lab, such as GIA, has the technology and expertise to discern whether your diamond is a natural diamond, diamond simulant, imitation diamond, or a synthetic diamond. In addition, a GIA Diamond Report will not only identify the diamond, but also provide an unbiased analysis of the 4Cs of your diamond: color, cut, clarity, and carat weight.  

While our definitive Diamocycle Guide is no substitute for a diamond certificate from GIA, as always, it is our pleasure to offer you all the information possible to allow you to move through your life with confidence, clarity, and peace of mind. 


For more information on where to sell a diamond, please see our previous guide: Best Places to Sell Loose Diamonds or Diamond Jewelry 



MYTH: A real diamond has inclusions. Fake diamonds are perfect. 

FALSE PROCEDURE: Use a jeweler’s loupe to examine your loose diamond or diamond jewelry. 

For the uninitiated, a jeweler’s loupe is a small magnifying glass used by jewelers in the industry. 

To begin, for the unskilled, it is rather difficult to spot inclusions (or imperfections) on a diamond using a loupe. Often the reflections and facet junctions can make it difficult to see inclusions. In addition, some loose diamonds are flawless and include no inclusions, making the use of the loupe or the conditionality of inclusions to be faulty ways of how to tell if your diamond is real or false. 

Beyond that, while most authentic diamonds will have inclusions, it would be incorrect to assume that imitation diamonds will not have inclusions. (They might be added in attempts to further promote “authenticity.”) In addition, some glass diamonds will have gas bubbles, which can easily look like natural inclusions.

Lastly,  there are many other natural gems (that include inclusions, but are not diamonds) that might look like diamonds to the non-professional eye. These gemstones include colorless topaz, colorless zircon, and colorless sapphire. Which is not to say, inclusions does not a diamond make and they are not a reliable way of how to tell if your diamonds are real!  


What are synthetic diamonds? 

As we dive into the nitty-gritty of loose diamonds and diamond jewelry, you may be wondering what the difference is between a synthetic and a natural diamond. Many gemstones have synthetic or lab-grown counterparts. These synthetic stones have the same crystalline structure, chemical composition, and physical properties as natural gemstones, but have, of course, been created in a lab. 

Some synthetic gems, such as synthetic rutile, colorless synthetic spinel, and colorless synthetic sapphire both have a natural counterpart and look surprisingly like a diamond. 

There are also some synthetic substances that have no natural counterparts, such as YAG (yttrium aluminum garnet), GGG (gadolinium gallium garnet), CZ (synthetic cubic zirconia), and synthetic moissanite, which look like a diamond but are not actually diamonds – synthetic or natural. 


MYTH: Synthetic diamonds are not real diamonds. 

FALSE PROCEDURE: A jeweler’s loupe is a good way of how to tell if your diamond is real (natural) or synthetic. 

Synthetic diamonds actually are real diamonds! Synthetic diamonds are both man-made and have the same properties as natural diamonds. While the price between natural diamonds and lab-grown diamonds is considerable, it would be incorrect to consider synthetic diamonds as “fake” diamonds. Lastly, as the physical properties between synthetic diamonds and natural diamonds are identical, it is impossible to tell the difference between a synthetic diamond and a natural diamond via a loupe. The only way to determine, as such, is by laboratory testing. 

So, while synthetic diamonds may not fetch you the same price as a natural loose diamond or diamond jewelry, we encourage you to remember that synthetic diamonds are actually diamonds as well. 


MYTH: Real diamonds have sharp edges and fake diamonds will not. 

FALSE PROCEDURE: Examine your loose diamond for sharp edges. If it has them, it’s a real diamond. 

While it is true that imitation diamonds that are made in a mold (often plastic or glass) lack sharp edges, synthetic diamonds and other imitation diamonds made from other gems will also have sharp edges. 

Thus, while you can use “The Edge Test” to tell gemstones from molded items, you can not use the edge test to tell between natural diamonds, other gemstones, and synthetic diamonds, rending “The Edge Test” an unhelpful tool in how to tell if your diamond is real. 


MYTH: You can determine a natural diamond by the quality and metal of its setting. 

FALSE PROCEDURE: Examine the quality of the setting to determine the authenticity of your stone. 

While some may believe that natural diamonds are exclusively set in valuable metals, such as gold or platinum, the setting metal is an incredibly inconsistent and inaccurate way of how to tell if your diamond is real. 

Given the high price of gold and platinum, some valuable natural diamonds are set in silver, and antique diamond jewelry is often set in a mix of gold and silver. Given the variety of metal settings for both natural diamonds and imitation diamonds, we strongly discourage you from using the setting metal in the attempt of  how to tell if your diamonds are real. 

Similarly, the quality of the setting is not a great indicator of how to tell if your diamond is real. While one might assume that a high-quality diamond jewelry setting belies a high-quality stone, a poor quality setting might be holding a natural authentic diamond, and simply have survived a lot of wear or tear or be a result of the work of a shoddy jeweler. 


MYTH: Diamonds can’t be scratched.

FALSE PROCEDURE: Rub the gem with sandpaper. Real diamonds won’t be scratched. 

This is a damaging test and should never be used! As the hardness of sandpaper is a 7 and 9 on the Mohs scale, it can often damage a diamond, whether it is natural or not. With the value of your loose diamond or diamond jewelry in mind, we strongly recommend never attempting “The Sandpaper Test,” as regardless of its veracity, you can damage your stone, further devaluing it, regardless of whether it was real or not. 


MYTH: Natural diamonds can’t be broken by heat. 

FALSE PROCEDURE: Fill a glass of water with cold water. Heat the stone for 40 seconds and then drop the stone in cold water.  If the stone shatters, it was made of weaker components and was not a real diamond. A true diamond will show no reaction. 

As diamonds are made of incredibly strong materials and are unresponsive to heat, technically, this is a way you can use in how to tell if a diamond is real.  

That said, as mentioned, synthetic diamonds are diamonds too, and this test will not differentiate between natural and synthetic diamonds. In addition, we encourage you to use this test sparingly, as it will destroy the stone you have, if it was not a real diamond! We encourage you to consider whether the truth is worth the possible destruction of the loose diamond or diamond jewelry you have. 


MYTH: Real diamonds will not fog. 

FALSE PROCEDURE: Breath on the diamond. If it fogs, it’s not a real diamond. 

This is an incredibly unreliable way of how to test a diamond. Advice on the internet doesn’t articulate how long one should breathe or how large the diamond surface must be. While natural diamonds will not fog, synthetic diamonds will behave the same way (also not fogging), further obscuring the results of your very unreliable test. In addition, ambient humidity might affect your results, further complicating the reliability of this test. 


MYTH: Real diamonds “sparkle.” 

FALSE PROCEDURE: Check for the sparkle. If it sparkles, it must be a diamond.  

While there is specific sparkling that jewelers refer to in loose diamond or diamond jewelry (it’s called scintillation), it is incredibly difficult to discern the scintillation of a diamond from the sparkle of an ordinary gemstone. To the untrained eye, many faceted gems, such as synthetic moissanite, synthetic cubic zirconia (CZ), or a colorless natural zircon will sparkle in a way that is similar to a diamond’s scintillation. 


What is scintillation? 

A natural diamond’s scintillation refers both to its sparkle and the pattern of light and dark that is caused by areas of reflection within the loose diamond or diamond jewelry. Along with scintillation, other factors that you might see in a diamond’s “sparkle” include the diamond’s brightness (the externals and internal white light that are reflected from a face-up view), and fire (how the white light scatters like a rainbow). That said, both brightness and fire are qualities that both diamonds and other gemstones have, making them unreliable factors for determining a diamond’s veracity. 


What makes a loose diamond or diamond jewelry shine? 

To further convince you why scintillation is a poor judicator in how to deal if a diamond is 

real, a diamond or gemstone’s scintillation also depends on the following factors: 

  • Cutting Style: Even if two diamonds have the same number of facets and the same shape, the cutting style will play a crucial part in the brightness of the diamond, making brightness an inaccurate way of how to test a diamond.  

  • Number of Facets: The more facets a diamond has, the greater its ability to bounce and scatter light. An imitation diamond with more facets may shine far more than a natural diamond with a lower facet cut. Again, the perceived sparkle of a diamond is an inaccurate way of how to test if a diamond is real.  

  • Cut Quality: Likewise, a poorly cut natural diamond is still a diamond, but may not deliver the same shine that you’d expect of natural diamond. Just because it doesn’t sparkle, doesn’t mean it’s not a diamond. 

  • Lighting: A change of lighting will absolutely change the sparkle of the stone you’re holding. Again, do not rely on the sparkle of the diamond to decide whether it’s real or not (it might just be your lighting!). 

  • Cleanliness: Lastly, the cleanliness of your diamond will affect its shine, again making shine an unreliable decider of whether your stone is authentic or not. 


MYTH: You can’t see through a real diamond. 

FALSE PROCEDURE: Look at a newspaper through a diamond. If it’s a real diamond, you won’t be able to read the type. 

Again, this is a problematic test in how to tell if your diamond is real. The faulty logic assumes that a well-cut diamond is highly refractive, which would cause the light to bend as it moves through the loose diamond or diamond jewelry. Given this bending, it would be impossible to read the text straight through a diamond. 

While this is a test that works well for gemologists, it can be very confusing for the unskilled professional. It should never be used as a deciding way of how to test a diamond, as many variables can affect the reading of the newspaper. To give you a sense of how fickle this test is – some factors that affect “The Newspaper Test” are: the lighting conditions and surroundings, the cleanliness of the stone, its placement on the newspaper, the tester’s eyesight, the mounting of the stone, and its shape and proportion. Given all that, please do not rely on a newspaper to decide anything about your loose diamond or diamond jewelry ! 


MYTH: Real diamonds sink; everything else floats. 

FALSE PROCEDURE: Put your diamond in a glass of water- if it sinks, it’s a diamond. 
As diamonds have a high density, a real diamond will sink in a glass of water. That said, diamond substitutes and imitations have lighter densities and will float to the middle or top of the glass. That said, there are plenty of gemstones that are equally or more dense than diamonds, so while this test can tell you if your stone isn’t a diamond, it’s not a reliable way of how to test if your diamond is real and most definitely a diamond. 


MYTH: Real diamonds are always a deep blue under a UV light. 

FALSE PROCEDURE: Hold your diamond under a UV light – if is blue, it’s a diamond. 

Much like the water test, this can tell you if your stone is NOT a diamond, but is a little less conclusive as to if your stone is actually a diamond. Under UV light, most diamonds will reveal a blue fluorescence. While a medium to strong color of blue confirms that you do have a diamond, not all diamonds reveal a blue fluorescence, again rendering this way of how to test a diamond helpful but not conclusive.  


Given the many diamond myths and false procedures, what’s a diamond owner to do? 



Below are a few viable solutions on how to test your diamond and see whether or not the diamond you have is real or fake. 


OPTION 1: Use a Thermal Conductivity Probe (aka “The Diamond Test”) 

Because diamonds are effective heat conductors, a real diamond will disperse heat rapidly after being warmed. With this in mind, using a thermal conductivity probe can be a helpful test in how to tell if a diamond is real. 

If the loose diamond or diamond jewelry disperses heat at a slower rate, the diamond is not real. That said, it’s worth noting that synthetic moissanite stones have a similar or equal heat disbursement as real diamonds, which renders this test inconclusive with moissanite. That said, refer to our Diamond Versus second to understand specific differences between diamonds and other stones.  


OPTION 2: Use an Electricity Conductivity Test 

Similarly, diamonds conduct electricity better than other stones, including synthetic moissanite. With this in mind, jewelers and gemologists often use an electricity conductivity test to determine whether a diamond is real or fake. An electricity tester will provide conclusive results in how to know if a diamond is real. A diamond will show conductivity while other stones like moissanite and cubic zirconia will not. 


OPTION 3: Conduct High Profile Weighing

Another way that jewelers and gemologists determine if diamonds are real is with very finely tuned scales for measuring small differences in weight. Real diamonds will weigh less than fake stones of the same size. While this is a reliable method in how to test a diamond, it requires you to have a special scale for weighing carats and a fake diamond that is about the same shape to use as a comparison. 




Diamond vs. ______________ ? 

In this section of our definitive guide, we articulate some of the most important differences between diamonds and other stones that look like diamonds. Our hope is that by combining the above tests of how to tell if a diamond is real with these specifics, you’ll be better able to determine whether your loose diamond or diamond jewelry is real or fake. 


Diamond vs Moissanite

Given the remarkable visual similarities between diamonds and moissanite, here are a few ways to tell the difference: 

  • Via Microscope: At 1200x magnification, a diamond’s inclusions or the lack thereof of moissanite will become visible and a viable way to tell the difference. 

  • Electric Conductivity Test: As diamonds conduct electricity better than moissanite, this is a valid way to determine the difference. 

    • (Please note that a thermal conductivity test will not tell you the difference, as moissanite and diamonds have nearly identical thermal conductivities!) 

  • X-Ray Examination: Diamonds are radiolucent, while other stones such as moissanite, are radiopaque. Sending your stone to a professional testing center with an x-ray machine is a very reliable way of how to tell if a diamond is real. 


Diamond vs Cubic Zirconia

  • X-Ray Examination: As mentioned above, Cubic zirconia is also radiopaque, making an x-ray examination a viable way to determine the veracity of your stone. 

  • High Profile Weighing: Cubic zirconia weighs more than diamonds, allowing you to conduct a weight test if you have two stones of similar size. 

  • Light Reflection: Cubic zirconia also reflects orange-tinted light, as compared to the shades of grey that are emitted by diamonds. 

  • Presence of Inclusions: Cubic zirconia often doesn’t have inclusions, while diamonds often do. As per above, this is not a conclusive way of how to test a diamond across the board, but can help determine if your stone is cubic zirconia or not. 


Diamond vs White Sapphire

  • Sparkle and Contrast: While white sapphires often look like diamonds, white sapphires will not have the standard contrast of light and dark areas that a diamond has, and often also lacks the diamond’s signature sparkle. If the light and dark parts of the stone seem to be blurred, odds are high you may have a white sapphire.  


Diamond vs White Topaz

  • Scratch Test: While white topaz might look like diamond at first glance, topaz is softer than diamond and much more easily scratched by other materials. If you look closely at the surface of your gemstone and see scratches, odds are it is not a diamond, but instead a stone such as white topaz. 


Natural Diamond vs Synthetic Diamond

Given that synthetic diamonds are diamonds, but differ greatly in resale value and pricing, it’s both essential and incredibly difficult to tell the difference between a natural diamond and a synthetic diamond. 

  • Conductivity Test & High Magnification Examination: Given the difficulty of telling the difference between these two stones, we recommend a combination of these two ways of how to test a diamond done by a professional to tell the difference. 


Myth: All Diamond Certificates Are Real?
False Procedure: Verify the report online.

Diamond certificates, also known as grading reports, are documents issued by independent gemological laboratories that provide a detailed analysis of a diamond’s characteristics, such as its carat weight, color, clarity, and cut. These certificates help buyers determine the value of a diamond and make informed decisions when buying one.

However, fake diamond certificates are also prevalent in the market, and it is essential to know how to authenticate them. It is possible for a fraudster to use a real diamond certificate number on a fake report. Here are some tips to help you verify the authenticity of a diamond certificate:

Option: Check The Labs Credentials

Check the issuing laboratory’s credentials: Only trust certificates issued by reputable and well-known laboratories such as GIA, AGS, IGI, and EGL. Avoid certificates from unknown or lesser-known labs as they may not have the same level of expertise and credibility.

Verify the certificate number:

Each diamond certificate has a unique number corresponding to the specific diamond it represents. Make sure the certificate number matches the number laser inscribed on the diamond’s girdle. However fake inscriptions matching real diamond reports have become an issue, so an expert may be needed to verify your diamond is in fact the actual diamond in the report by examining its unique characteristics which can not be falsified. An example would be the position of a noted inclusion.

Check for security features:

Most legitimate diamond certificates have security features such as holograms, watermarks, and microprint. These features are difficult to replicate and can help you identify a fake certificate.

Look for spelling and grammatical errors:

Fake diamond certificates often have typos, errors, or inconsistencies in the text, which is a red flag that it may not be genuine.

Compare the diamond with the certificate:

Finally, compare the diamond’s characteristics listed on the certificate with the actual diamond. If there are significant discrepancies in the information, it could indicate that the certificate is fake or that the diamond has been tampered with.

Diamond certificates can be a useful tool in determining a diamond’s value and quality. However, it is crucial to verify their authenticity to avoid being scammed. By following the tips mentioned above, you can authenticate a diamond certificate and make an informed decision when buying a diamond.

At Diamocycle, we take pride in providing our customers with genuine, high-quality diamonds at fair prices. We believe that transparency and honesty are the keys to success in the diamond industry, and we strive to educate our customers on how to identify real diamonds. Whether you’re looking to buy or sell a diamond, you can trust Diamocycle to provide you with the best service and expertise in the business.

As always, the world of loose diamonds and diamond jewelry is fascinating, complex, and full of beauty. As always, we strongly recommend obtaining a GIA certificate to ascertain the veracity of your diamond and contacting us should you ever need any assistance or further information in determining the next steps for your stone. 


As always, 

Your Neighborhood Jeweler,