How to tell if a diamond is real?
If you’re looking for a diamond, you’ve got your work cut out.
Not only do you have to find the perfect diamond, but you also have to make sure it’s authentic.
No easy task when there are so many fakes out there!
How to tell if a diamond is real? Let’s get to the bottom of it.

Lab-made diamonds account for only a small percentage of total diamond sales, but that number is growing fast.
These artificial gemstones look precisely like their mined counterparts, but they’re much cheaper and easier to produce.
With the growth of lab-made variations, there are also several inexpensive gemstones, such as cubic zirconia and moissanite, which look like diamonds.
Moissanite offers an extraordinary brilliance with 9.25 on the Mohs Scale of hardness (diamond’s hardness is 10).

Then, there is cubic zirconia that mimics various diamond shapes with an aesthetic brilliance.
This gemstone is cheaper than natural diamonds and looks very similar to them—so similar that many people can’t tell the difference.
Other less expensive gemstones resembling diamonds are colorless topaz, zircon, and sapphire.
Some lab-created gems, including gadolinium gallium garnet and yttrium aluminum garnet, will also look like diamonds to an inexperienced eye.

Think about a family heirloom or your precious engagement ring. Wouldn’t you be incredibly sad if that turns out to be fake?
But don’t worry. There are several tests to prove the authenticity of diamonds, and most of them you can perform at home.
How to Tell If a Diamond Is Real: 12 Tests to Clear Your Confusion
So, we’ve rounded up 12 tests and methods that can tell whether your diamond is real or not.
You can carry out most of them by yourself, while others will need professional tools and skills.
1. The Scratch Test

- What’s tested? Diamond’s hardness
- Tool? A plate glass
- DIY or Professional method? DIY
- Mounted or Loose Diamond? Loose
- Difficulty level? Easy
- Conclusive? No
The Method:
Diamond is one of the most rigid materials, and it’s got a perfect 10 score on the Mohs Scale of Hardness.
So, it can scratch almost all substances, including glasses.
Take a plate glass and place it on a plain surface. Then, scrape a loose diamond on its surface.
A real diamond will scratch the glass surface, but it’s still not the most effective way because a moissanite or cubic zirconia will produce the same result.
Also, scratching on such a hard surface can damage the diamond itself, so you must be careful.
2. How To Tell if a diamond is Real With The Floating Test

- What’s tested? Diamond’s density
- Tool? Water
- DIY or professional method? DIY
- Mounted or loose diamond? Loose
- Difficulty level? Easy
- Conclusive? No
The Method:
The floating test is a super-easy way to test a diamond’s authenticity. Take a glass full of water, drop the loose diamond there, and see if it floats or sinks.
If it sinks to the bottom and stays there, it’s probably authentic. Diamonds have a high density, which is three times more than the density of water.
So, they can easily overcome the water pressure when sunk. A fake stone will float underneath or at the surface of the water.
However, the result is still inconclusive because some fake diamonds will sink into the water.
3. The Fire or “Shatter” Test

- What’s tested? Diamond’s tensile strength
- Tool? A lighter, cold water, a pair of fireproof gloves or pliers
- DIY or professional method? DIY
- Mounted or loose diamond? Loose
- Difficulty level? Medium
- Conclusive? No
The Method:
Diamonds have tensile strength because they are formed under intense pressure and heat.
For this reason, they are resistant to high heat, so the structure can well endure the shock of rapid temperature change.
Take a small bowl or glass and fill it up with cold water. Now, wear a pair of fireproof gloves or hold the stone with a set of pliers.
Heat the stone for around 30 to 40 seconds with a lighter, and then drop it straight into the cold water.
Nothing will happen if it’s an original diamond. A synthetic cubic zirconia or fake glass stone will shatter because its weak components cannot endure the quick expansion and contraction because of heat and cold exposure.
However, it is not foolproof because a few more diamond-like natural and lab-grown gemstones will also pass this test.
Some stones that will show almost zero heat sensitivity are moissanite, gadolinium gallium garnet (GGG), white topaz, yttrium aluminum garnet (YAG), and white sapphire.
4. How to Know if a diamond is real With The Diamond Scale Test

- What’s tested? Diamond’s weight
- Tool? A special weighing scale and a real diamond (of the same shape and size)
- DIY or professional method? Professional
- Mounted or loose diamond? Loose
- Difficulty level? Medium
- Conclusive? Depends
The Method:
Professional jewelers use a unique scale for measuring the weight of the gemstones.
It’s a fine-tuned scale because the weighing has to be highly accurate.
The jeweler will first take the weight of a fake stone having the same shape and size as the stone to be tested.
The fake one will weigh more than the real one.
To make the test process easier, it’d be better to compare the weight against cubic zirconia because its weight is around 55% more than a diamond of the same shape and size.
Testing becomes more manageable if your stone already has a GIA diamond grading report.
In that case, the stone’s weight just needs to match that report.
5. How To Tell if a diamond is Real With The Newspaper Method

- What’s tested? Diamond’s refractivity
- Tool? A newspaper and bright lighting
- DIY or professional method? DIY
- Mounted or loose diamond? Loose
- Difficulty level? Easy
- Conclusive? Almost
The Method:
Diamonds refract light, so much so that it’s almost impossible to see something clearly through them.
By using this property, you can tell whether your precious diamond is natural or not.
Now, look through the stone and try to read the text. If the letters are clear or a little blurry but still readable, it’s clearly a fake one.
Diamond’s refractivity sends light in various directions instead of straight lines.
For this reason, you cannot see anything clearly through it.
6. The Dot Test

- What’s tested? Diamond’s refractivity
- Tool? A white paper and pen
- DIY or professional method? DIY
- Mounted or loose diamond? Loose
- Difficulty level? Easy
- Conclusive? Almost
The Method:
This is almost a carbon copy of the newspaper test, but you will use a pen and paper to check the diamond’s refractivity.
Draw a small dot on a piece of white paper and place the diamond with its face down.
Don’t forget to clean the stone before the test. Now, try to see the dot through the stone’s pointed pavilion.
If it’s a genuine diamond, you will not see the dot underneath clearly because of the diamond’s random refraction.
A fake stone will show the dot clearly, and you can also spot a circular reflection inside it.
7. How to Tell if a Diamond Is Real With Fog

- What’s tested? Diamond’s heat conduction
- Tool? Your breath
- DIY or professional method? DIY
- Mounted or loose diamond? Both
- Difficulty level? Easy
- Conclusive? Yes
The Method:
Hold the diamond between your two fingers and fog it up with your breath. A real diamond will clear that fog up almost instantly.
However, it will take a few seconds for a fake stone.
Diamonds have an excellent head conduction ability. Since they are super quick in dispersing heat, the fog on the surface dissipates in one or two seconds.
Other materials don’t have such good heat conduction ability, so the mist does not vanish before three to four seconds.
8. How To Tell if a diamond is Real With with Black or Ultraviolet Light Test

- What’s tested? Diamond’s fluorescence
- Tool? UV light
- DIY or professional method? DIY
- Mounted or loose diamond? Loose
- Difficulty level? Easy
- Conclusive? No
The Method:
Diamonds are fluorescent, so they emit a bluish glow under ultraviolet (UV) light.
So, place your diamond under UV light and see how it glows.
Normally, a fake diamond won’t emit such fluorescence. However, not all diamonds turn blue under this light.
So, you cannot 100% rely on this test.
9. How to Tell if a Diamond Is Real With a Loupe

- What’s tested? Diamond’s imperfections
- Tool? A special magnifying glass (loupe) and a tweezer
- DIY or professional method? Professional
- Mounted or loose diamond? Good for loose diamonds
- Difficulty level? Medium
- Conclusive? No
The Method:
Jewelers and gemologists use a loupe (a small but powerful magnifying glass) to spot the imperfections in diamonds and other gemstones.
A natural diamond has plenty of imperfections across its body. It will also have tiny mineral flecks that contribute to slight color changes.
Depending on the clarity grade, the level of blemishes will be between minimal and highly noticeable.
Mined diamonds are imperfect, which means they will have some blemishes. A lab-grown diamond and synthetic stone won’t have these inclusions.
Some genuine diamonds could be completely spot-free, but they are extremely rare.
You can do the test yourself by buying a loupe from a retail store. If not, take the diamond to a jewelry store.
10. How to Tell if a Diamond Is Real With a Magnifying Glass

- What’s tested? Diamond’s imperfections
- Tool? A magnifying glass
- DIY or professional method? DIY
- Mounted or loose diamond? Loose
- Difficulty level? Easy
- Conclusive? No
The Method:
It’s almost like the previous testing method, but you will use a standard magnifying glass instead of a loupe.
It’s the alternative method if you can’t manage a loupe or don’t want to take the diamond to a jewelry store.
Place the stone on a level surface and examine it through the glass. You should be able to see some imperfections and flecks.
The stone is probably a lab-made or fake one if there is none.
However, the method is still not conclusive because it’s not possible to spot all inclusions with a regular magnifying glass.
Also, some natural diamonds could be flawless, although they are extremely rare to find.
11. How to Tell if a Diamond is real Using a Diamond Tester

- What’s tested? Diamond’s thermal or electrical conductivity
- Tool? A thermal conductivity probe or meter
- DIY or professional method? Professional
- Mounted or loose diamond? Good for both mounted diamonds and loose stones
- Difficulty level? Medium
- Conclusive? Depends
The Method:
Professionals use a thermal or electrical conductivity meter or probe to determine how good the gemstones are at transmitting heat or electricity.
We already know that diamonds are excellent heat conductors. So, a real diamond will transmit heat quicker than other gemstones.
A thermal tester heats the gemstone and determines its genuineness at the rate of heat circulation across the rock.
A natural diamond transfers heat faster than cubic zirconia, glass, and other gemstones.
So, it’s pretty easy for a thermal probe to detect if the stone is diamond.

To make the process easier, the tester gives a beeping sound if the tested properties match those of a diamond.
However, the test cannot give conclusive results if the specimen stone is moissanite.
Lab-grown moissanite stones almost produce the same results in the thermal conductivity probe.
Don’t worry. You can clear that confusion with a more sophisticated electrical diamond tester.
It uses electrical conductivity as the primary testing parameter, which is different for moissanite and diamonds.
An electrical tester can also identify synthetic diamonds.
12. Get Appraisal from a Diamond Appraiser

So, if you want to check your diamond’s originality or actual value, getting it appraised by a professional appraiser seems to be the best idea.
An appraisal will also help if you are trying to sell the diamond, making sure that it’s worth the price you’re asking for.
What is a diamond appraisal?

It refers to the professional evaluation of the value of a diamond. It’s usually performed by a certified gemologist who will examine the 4Cs (cut, color, clarity, and carat) and determine the value of your stone based on those factors.
A professional appraiser will look at all of these factors and several others.
They have to have knowledge and insight about the current retail prices and trends in the market.
They also should know whether or not your diamond has been treated with any enhancements that would affect its value (such as heat treatment or coloring).
Where to get a diamond appraiser?
Your local jewelry stores will have their in-house staff who can perform this service.
However, the expert there may not be GIA certified, so you should ask. Also, the appraisal may or may not come with a lab report from the GIA.

Such an evaluation may cost between $100 and $200, or even less than that amount.
You can also choose an online service like Worthy or WPDiamonds. These institutions offer a free appraisal and take a percentage (10 to 20 percent) if you sell to or through them.
However, it’s possible to get the assessment (for free) even if you decide not to sell.
There are also other companies that offer this service online and offline.
Always check their reputation and online ratings before trusting them with something that precious.
Online services provide access to more extensive networks of certified professionals than offline stores do (and it’s easier to compare prices).
Also, keep in mind that most online platforms offer free consultations where you can discuss your needs before committing (which saves both parties).
What should be the qualifications of a diamond appraiser?
Choose an appraiser who has experience in the industry. Without the proper knowledge, they may not determine the actual value of the diamond.
Also, make sure that they have been trained and certified by an industry organization like the Gemological Institute of America (GIA).
The GIA offers courses on how to properly evaluate diamonds so that their appraisals are accurate.
How To Tell If A Diamond is Real: Final Words
You can perform the home tests we’ve mentioned to determine whether your diamond is fake or real.
However, these tests will only give you enough proof to decide whether or not you should be suspicious of your precious stone or not.
How to tell if a diamond is real or fake is a science in itself…
Only a professional jeweler or gemologist can provide conclusive evidence about the genuineness.
They have the necessary tools to examine the stone and the mastery to certify its originality.

FAQs about How to Tell If a Diamond Is Real
Q. How To tell if a diamond is real at home?
A. There are several methods to test a diamond’s authenticity at home. The easiest of the ways are water, fog, and scratch tests.
You can also perform the newspaper and fire tests for further assurance.
Q. Is there an app to test diamonds?
A. You can use Gemetrix Jewellery Inspector (available for Android and iOS devices) to detect synthetic and treated diamonds.
It uses PhotoLuminescence (PL) technology to determine the stone’s authenticity.
The fluorescence’s color and intensity change depending on whether the diamond is real or fake.
Q. How do you test a diamond with water?
A. It’s one of the easiest ways to test a diamond’s authenticity. Just drop a loose diamond into a glass of water.
A real one will sink to the bottom, while fake ones will float.
Q. How can you distinguish between cubic zirconia and a real diamond?
A. Cubic zirconia is a cheaper diamond look-alike, and it’s slightly challenging to spot the differences just by looking at it.
But if you look carefully, you will see that cubic zirconia stones are almost colorless and don’t have any inclusions.
A real diamond will show inclusions and blemishes under a microscope.
Tags: how to tell if diamond is real, how to tell if a diamond is fake, diamond jewelry, real diamonds