Unless you understand a diamond's structure and components, you might mistakenly believe that a gemstone is a diamond when it's entirely different, like cubic zirconia or moissanite. This is why it's essential to spot a fake diamond.
Although this guide is functional and practical, it should not be regarded as conclusive as a single test at home. An experienced diamond expert has the necessary equipment and experience to determine whether a diamond is genuine or fake.

How to Tell if Diamond is Real or Fake

A fake diamond can be distinguished from a real one by following the following steps:

Water Test

You can make sure a diamond is real by using this simple test.
Fill the glass with water to 34% of its capacity. Into the glass, drop the loose stone carefully. Diamonds sink if they are real. If it floats beneath or at the water's surface, you've got a fake. The water test determines whether your stone matches the density of a real diamond.

Fog Test

The fog test involves holding the diamond or ring between two fingers and blowing on it with a puff of air. Your breath will create a light fog on the diamond due to moisture and heat. Diamonds that dissipate immediately are real diamonds. It is likely a fake diamond if the fog takes several seconds to disperse. Heat dissipates quickly through diamonds due to their effective conductivity.

Check Diamond Setting and Mounting

Look at the type of setting and mount used on anything such as a necklace, bracelet, ring or other types of the ring that already has a diamond.
Real diamonds are only set in high-quality diamond jewellery due to their high price tag. Typical setting materials for real diamonds include white gold, platinum, yellow gold, pave setting, and halo setting.
Check the jewellery’s centre for markings to determine if the setting is as described. The marking in the jewellery indicates gold types such as 10K, 14K, and 18K. A platinum item is marked with the letters PT and Plat. Some markings indicate platinum and gold, such as 585, 770, 900, and 950.
Unless otherwise indicated, cubic zirconia gemstones are not real diamonds and are stamped or engraved with "C.Z.".

Try Heating The Stone And Seeing If It Shatters.

High heat will not affect diamonds since they are made of solid material.
You can test the authenticity of a diamond using cold water by filling a drinking glass with it. To hold the stone, use pliers or fireproof gloves. Drop the stone directly into the cold water after heating the stone for approximately 40 seconds with a lighter. Diamonds that break are made from weaker components and are not real diamonds. There will be no reaction from a genuine diamond.
The heat test tests stone quality and strength. Weak materials, such as glass or cubic zirconium, crack and break when heat expands and contracts rapidly. You probably use Pyrex or glass dishes for cooking. The shock in temperature change may shatter the dish as soon as you remove it from a hot oven.
Likely, diamonds will not be damaged by such heat tests since they are among the strongest materials on earth. Temperature changes won't affect the diamond because heat disperses quickly.

UV Light Test

You can test a diamond's authenticity by placing it under a UV light and watching its reaction. It is common for diamonds to emit a blue glow, but not every diamond will do so. A diamond that does not glow under UV light does not glow under regular light. The results may not indicate that the stone is a fake diamond if the stone does not glow.
The stone should be tested with advanced equipment by a diamond expert or jeweller since this test isn't definitive.

At-Home Diamond Refractivity Test

Light bends and refracts in a diamond, which is why it sparkles. A diamond's table (the top, flat surface) reflects and bounces light when it strikes its pavilions (the angled surfaces on the lower half of the diamond). Having brilliance means that a diamond sparkles brilliantly when it does this well.
Cubic Zirconia, for example, is not a diamond, so it does not refract light as well. If they have any brilliance at all, it will be minimal.
The following tests can be used to determine a diamond's refractivity.

Newspaper/'Read-Through' Effect

Put a diamond flat side down on a newspaper page with lots of lettering to test its refractive properties. Diamonds should be illuminated brightly, and no shadows should be cast on them by objects or people.
A fake diamond can be detected even if you can read the letters in the newspaper. Rather than refracting light straight, diamonds will refract it in different directions. As a result of this refraction of light, you will have trouble reading the letters on the paper through the diamond.
Loose diamonds are the best candidates for the newspaper test. Consider using the fog test if the diamond is already set or getting an expert to review it.



The Dot Test

A dot test is an excellent alternative to a newspaper if you don't have any.
Take white paper and draw a small dot with a pen. With the flat side down, place the stone on the dot. By looking down through the diamond, you can see the paper below. The gemstone is fake if there is a circular reflection inside. Diamonds are real if there is no dot or reflection in them.
Rather than bouncing straight, the light will bounce in different directions when it passes through a genuine diamond. Natural diamonds, real diamonds, cannot be seen through letters or dots.

At-Home Diamond Reflectivity Test

Furthermore, you can test a stone's reflectivity and refractivity. The refractive property refers to which direction the light bounces, while the reflectivity property refers to how much and how well the stone reflects light.
A diamond's table's reflection is composed of brilliance (white light sparkle) and fire (coloured light).

Sparkle Test

Sparkle tests don't require any special equipment-just your eyes. Take a standard lamp and place the diamond under it. You can see how the stone reflects light. Does the diamond appear to be shimmering with white light? Is there also a colourful reflection of light?
Diamonds reflect white light exceptionally well, providing exceptional sparkle. Coloured light, or fire, is also reflected magnificently by diamonds.
You will notice a drastic difference in the colour and white sparkle of a real diamond compared to a fake diamond-like Cubic Zirconia.

Diamond Authentication Techniques

Various tests can determine the difference between a genuine diamond and a synthetic diamond, but it's recommended that you consult a professional diamond expert for assistance. You can determine the authenticity of diamonds only if you consult a gemologist with a Graduate Gemologist (GG) degree.
Diamond professionals use several proven methods and tools for determining if a diamond is genuine, giving you peace of mind.

Inspecting A Diamond With A Loupe

Loupes, specially designed magnifying glasses used for diamonds and gemstones, are available to diamond professionals. A professional uses a loupe to detect blemishes and imperfections within a diamond. There are slight imperfections called inclusions in diamonds, which sets a diamond apart from a fake diamond.

Thermal Conductivity Probes

A thermal conductivity probe or meter is usually used alongside a loupe by gemologists. The thermal conductivity of gemstones will be determined using this tool. In addition to being influential heat conductors, diamonds also disperse heat rapidly when heated.
Diamonds are not real if they disperse heat slowly. Moissanite synthetic stones often behave similarly to real diamonds. The diamond tester available on the market can be chosen. Take a look at the example on the right from Amazon.
A fake diamond test

High-Profile Weighing Of A Real Diamond

Jewellers and gemologists generally use excellent scales to measure small weight differences. Unlike fake stones like Cubic Zirconia, real diamonds weigh less and can only be detected with unique scales for weighing Carats.
Choose a fake diamond with approximately the same size and shape as the real one. If you are considering a diamond, use this stone as a comparison.

ElectricalConductivity Can Be Used To Detect Fake Diamonds

Jewellers or gemologists can also test the conductivity of electricity to detect fake diamonds. Moissanite, a synthetic stone, does not conduct electricity as well as diamonds.
When an electricity tester tests a stone, it will be clear whether it is real or artificial. Moissanite and cubic zirconia do not show conductivity like diamonds.

Comparing A Real Diamond To A Moissanite

It's essential to use a jeweller's tools to test for the authenticity of moissanite since synthetic moissanite is increasingly available on the market. It is possible to detect whether a diamond is real or fake almost instantly with the help of these tools.

A Microscope For Examining

A jeweller or gemologist can scrutinise a stone using a power microscope at 1200x magnification. It will be possible to identify inclusions in diamonds and small differences between real diamonds and moissanite at this level of magnification.

Examine Your X-Rays

Having a stone's internal molecular qualities examined by a professional diamond lab is the best way to find out what it is made of. X-ray machines will determine a stone's radiolucent or radiopaque molecular structure. The radiolucence of diamonds is distinct from fakes like cubic zirconium and crystals, which have more radiopaque characteristics.

How Reliable Is The Scratch Test For Diamonds?

The scratch test was one of the most commonly used methods of determining a gemstone's hardness. To see if the loose diamond would scratch the mirror or the stone, the loose diamond was scraped across a mirror.
The materials used in diamonds make them highly durable and scratch-resistant, but cubic zirconia and moissanite are also relatively durable and scratch-resistant. These factors make the scratch test unreliable. Rather than using a thermal conductivity test or a loupe tool to inspect the diamond, you should use other tests.

Identifying Other Stones That Aren't Diamonds

Other gemstones are becoming increasingly popular, so here are some tips for spotting stones that look like diamonds.

Synthetic Diamonds: Recognizing Them

Since synthetic diamonds are becoming more prevalent, it's important to distinguish between lab-created and natural diamonds. There are many chemical and molecular similarities between synthetic diamonds and natural diamonds.
An expert should review the diamond because of its intricate internal qualities. A conductivity test can be conducted, and the stone can be examined under high magnification. The difference in value between synthetic and natural diamonds may not be apparent to the naked eye, but it is crucial for resale and insurance purposes.

Recognising Cubic Zirconia

It is easier to test cubic zirconia for authenticity than other fake diamonds. For example, you can easily measure a stone's sparkle and fire by using the sparkle test.
Aside from that, cubic zirconias reflect orange-coloured light. Also, they generally lack imperfections and inclusions and weigh more than real diamonds. An expert's microscope or the naked eye will reveal inclusions in real diamonds.

A Guide to Recognizing White Sapphires

It is common for sapphires to be available in blue, but they also come in various colours, including white, which appears clear to the naked eye. It is common to pose white sapphires as diamonds, but they do not possess the diamond's signature sparkle and contrast between light and dark areas.
The stone is likely to be a white sapphire if it appears more blurred in colour-i.e. it lacks distinct light and dark areas.

Moissanite Identification

Among fake diamonds, moissanite is perhaps the best actor. Diamond professionals are usually able to distinguish between the two with their expertise.
Moissanite and diamond are distinguished by their electric conductivity. Due to moissanite's nearly identical thermal conductivity to diamonds, the thermal conductivity test cannot be used to identify it.

Identifying White Topaz

Despite looking like a diamond at first glance, white topaz has several characteristics that distinguish it from real diamonds.
Other materials can easily scratch the exterior of the stone since it is softer than a diamond. To detect scratches, you can magnify a white topaz using magnification. The durable composition of diamonds prevents scratches.


This guide can use many tests to determine if a diamond is real, such as the fog and thermal conductivity tests.
As synthetic gemstone materials are numerous and complex, we recommend consulting a diamond expert or jeweller before using them. These experts can spot a fake diamond because they are trained to do so.
We guarantee you'll never have a problem knowing whether a diamond is real if you use our diamond education or experts. Before purchasing a diamond, you must ensure the diamond matches the GIA or AGS certificate.


Do sparkle diamonds exist?

A real diamond has a unique way of reflecting light: the inside sparkles greyish-white, while the outside reflects a rainbow of colours. Meanwhile, fake diamonds will have rainbow colours that can be seen both inside and outside.

Diamonds reflect light like mirrors, don't they?

In contrast, Diamond has a reflective index of 2.42, while Mirror-Like Effect Glass has a reflective index of 1.50. Because of this, it is impossible to see through a diamond. By reflecting the light, the ray of light creates a mirror-like effect.

Diamonds sparkle in what way?

Due to the absence of facets or faces that bounce and reflect light cannot bounce and reflect light. Light performance is what makes diamonds sparkle. In conjunction with its ability to reflect light, a diamond can transmit light that penetrates it, bounces around within it and ultimately returns light to your eye as it does so. The sparkle you see is that.

Are real diamonds foggy?

Breathing on your stone is the easiest way to test it at home. You are most likely dealing with a fake stone if it fogs up a lot and takes a while for the condensation to evaporate. Although diamonds fog up, it is only a small amount, and the condensation quickly evaporates.

Can diamonds be tested with an app?

With the help of an app, you can now detect the authenticity of diamonds and gemstones. An Android and iOS mobile application is now available from Khanna Gems.