Buying a diamond is an emotionally important purchase for many of us, so it is only natural that you’ll want to know the authenticity of the diamond, especially if it is for your engagement ring.
With the diamond market predicted to grow by USD 39.66 billion from 2022 to 2027, the presence of counterfeit diamonds in the e-retailing space will inevitably increase. The nature of online shopping, which limits physical inspection of the products, potentially allows counterfeiters to profit from selling fake diamonds. Consequently, verifying the authenticity of diamond jewellery becomes crucial to safeguard the consumer.
Fortunately, there are several tips and tricks on how to tell if a diamond is real or not.
“How to tell if a diamond is real?” That is a question that comes to many buyers’ minds. The market is heavily saturated with dupe diamonds that can easily be mistaken for the real thing - natural gemstones with a strong resemblance to diamonds, such as white sapphire, white topaz and colourless zircon, as well as synthetic diamonds like CZ (synthetic cubic zirconia,), and synthetic moissanite.
Being able to identify a real diamond from a fake is a critical skill to ensure that you’re making a genuinely worthwhile investment in your diamond jewellery. It can mean the difference between purchasing a genuine diamond ring and spending thousands on a cheaper fake.
Here are some steps you need to know before you buy a diamond.
The first step is to perform a visual inspection. An effective approach is to observe the stone's refraction of light by conducting these two simple tests.
Conduct a sparkle test using just your eyes by holding the stone under a normal lamp. Watch how the light reflects off of the gem. If you see both bright shimmers of white light and colourful light reflections bouncing from the gem, it is likely a real diamond.
A genuine diamond reflects white light extremely well, creating a brilliant sparkle. They also reflect coloured light, or fire, in an extraordinary fashion. By contrast, a fake diamond, such as cubic zirconia, will have a drastic difference in the white and coloured light sparkle compared to a real diamond.
Here’s how to tell if a diamond is real with a flashlight. You can also use sunlight for this test:
Place the gem close to the flashlight or in the sunlight.
Watch closely at the light shimmering through the gem.
A real diamond will have flaws, produce a brilliant gray and white sparkle within itself, and reflect a vivid rainbow pattern onto another surface.
By contrast, a fake diamond will be flawless and produce rainbow colours within itself, rather than sparkle, due to absorbing the light.
A diamond's ability to disperse light into a spectrum of colours is key to its light performance. Genuine diamonds have a high dispersion rate, producing a brilliant array of colours under light. In contrast, counterfeit diamonds typically show less vibrant colour dispersion. Thus, the quality of light performance—marked by brilliance, fire, and colour dispersion—reliably indicates a diamond's authenticity.
Learn more about light performance by Sarine.
It should be noted that these tests aren’t foolproof, as many synthetic diamonds are designed to have the same brilliance, shine and flaws as the real deal. So, it's important to perform other tests on how to know if a diamond is real.
Here are some popular DIY diamond tests you can conduct at your home to see if you have a genuine diamond or not:
Take a mirror and scratch the gem against it.
A hard stone will leave behind scratches on the glass.
The idea is that only a diamond is hard enough to scratch mirrored glass. However, many fake diamonds are made of equally durable materials, so this test isn’t perfect. This test may also run the risk of damaging your gem.
Fill a glass of water to roughly three-quarters full.
Drop the stone into the water and watch it sink.
A real diamond will sink to the bottom due to its density. If it hovers to the surface or partially sinks, it is a fake.
Diamonds are excellent thermal conductors. Here’s a simple test involving that trait:
Hold the stone between two fingers and breathe on it.
A light fog should form on its surface due to the moisture and heat.
Watch carefully at how quickly the fog disperses; the longer it takes, the less likely the stone is genuine. If the fog disperses almost immediately, the diamond is authentic.
Diamonds are one of the strongest substances in the world with excellent thermal conductivity; this makes them highly resistant to the shock caused by rapid temperature changes. This test uses high heat to test a stone’s durability, so use extreme caution and safety:
Heat the gem in an open flame (i.e. a lighter or bunsen burner) for thirty to sixty seconds.
Quickly drop the heated gem into a beaker of cold water.
The sudden temperature change will not affect a diamond. A glass or cubic zirconium will, however, shatter apart.
As this test involves destroying the stone IF it is not a true diamond, it is not recommended for any gems you might have a sentimental attachment to.
Draw a single black line on paper.
Place the gem on top of the line.
If you can see the line clearly through the gem, then its a fake. If the line disappears underneath the gem, then it's a real diamond.
Using a magnifying glass can help you search for imperfections (or lack thereof) in your gem. If your gem has flaws such as cracks, blemishes or bubbles, it is likely genuine. If it is free of imperfections, it is either a fake gem, a synthetic diamond or even a rare flawless diamond.
Hold the stone underneath a black light.
Most diamonds glow blue fluorescence under a black light. While not all diamonds glow blue, if yours does, it is likely genuine.
If your gem glows in different colours, such as green, yellow or gray, it is likely fake.
This is a suitable method if you do not want to remove the gem from its ring. A real diamond will usually be set into valuable metals like 14K / 18K white gold, rose gold, yellow gold or platinum, using a solitaire, halo, or pave setting. Look for small engravings on the inner band of the ring to confirm the setting details. If your ring has a ‘CZ’ stamp on it, then you would know with certainty that the stone is not a true diamond but a cubic zirconium.
While this guide is useful for getting a good idea of how a real diamond differs from a fake, no single DIY test should be regarded as conclusive. As such, it’s always best to get a certified gemologist to verify your diamond’s authenticity and quality.
If you’ve conducted any of the above at-home tests but are still concerned about your diamond’s authenticity, get a professional jeweller to verify your gemstone. Most professionals have high-tech tools that are far more reliable than DIY tests, so their findings will be more accurate.
A loupe is a small magnification device used by jewellers to view small details up close. Though they serve a similar function, the difference between a loupe and a magnifying glass is that a loupe doesn’t have an attached handle, and its lens frame is slightly more conical.
When looking through a loupe, a jeweller will search for inclusions. Mined diamonds normally have tiny natural perfections that indicate their authenticity. Whilst lab-grown diamonds normally lack flaws as they are made in controlled environments. This includes bubbles, cracks, small flecks of minerals and slight colour changes. Do note that some natural diamonds are flawless, which is very rare, but a lack of imperfections usually means that the stone is inauthentic.
To be sure, you can easily identify a diamond’s authenticity by looking for the laser inscription on a diamond's girdle through a microscope. At ZCOVA, our naturally mined diamonds are certified by the Gemological Institute of America (GIA), whereas our lab-created diamonds carry certifications from the International Gemological Institute (IGI).
This device works by measuring certain properties unique to diamonds. Two common tests utilising diamond testers are the thermal conductivity test and the electrical conductivity test.
Thermal Conductivity Test:
For this test, the stone is heated up and the tester measures its heat dispersion using a metal tip at its end. As diamonds as great thermal conductors, they will cool down quickly. Fake diamonds, on the other hand, will retain heat for a longer period of time, suggesting low thermal conductivity.
Electrical Conductivity Test:
Some testers can generate a small current of electricity to test a stone's conductivity. As diamonds are natural insulators, they will not conduct any electricity. If the stone conducts the current, it may indicate the presence of non-diamond material.
Jewellers usually have a very fine-tuned scale for weighing carats. These special scales are able to measure the minute differences between stones of approximately similar size and shape. Only these devices are able to tell you that a genuine diamond has a lower weight than a cubic zirconium.
We recommend consulting a diamond expert or jeweller. These experts are trained in ascertaining a diamond’s quality and spotting a fake diamond.
When buying diamonds, you must receive a diamond certification with your purchase. This is a formal document that contains detailed information about the specific diamond, and having it is a near guarantee of your diamond’s authenticity.
The Gemological Institute of America (GIA) Certification is the most reputable of all gem certification bodies. Diamonds that are GIA certified have undergone thorough testing by professional gemologists, using evaluations and grading criteria based on the ‘4Cs’: cut, colour, clarity, and carat.
By receiving a certification from the GIA, you can rest assured that you're getting a genuine diamond.
Learning how to tell if a diamond is real without a diamond tester is easy enough; as a rule of thumb, genuine diamonds are denser and more brilliant than most substitutes.
But the best method how to tell if a diamond is real or fake is, of course, to seek professional appraisal. A certified gemologist will be much better equipped to tell a real diamond apart from a fake.
If you’re concerned about your diamond’s authenticity, consult our experts at ZCOVA.
Need assistance with choosing the perfect diamond ring? Speak to our Curators online or make an appointment to visit our Galeria.
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