How To Tell If A Diamond Is Real Or Fake From Home

Determining whether a diamond is real of fake is a skill in itself and by no means an easy skill to learn.

Luckily for you the following guide will help you learn many ways to test a diamond for its authenticity, without the need for equipment, from the comfort of your own home.

Before you test a diamond to see if it’s real you should learn a little more about diamonds and what alternatives are used as “fakes”

About Diamonds

Diamonds are nearly 100% made up of carbon, under heat and pressure below the earths surface the atoms join together in a special and unique way.

The process takes place 100’s of miles beneath the earths surface and are pushed upwards by deep volcanic eruptions.

They are usually billions of years old sometimes as much as 3 billion years old.

Diamonds are near on indestructible and are the hardest natural substance known to man, in fact the only thing that can scratch a diamond is another diamond.

What alternatives are used

Most commonly there are 3 alternatives to diamonds which are far less expensive these are Cubic Zirconia, Rhinestone and Moissanite.

How to tell if a diamond is real

Check for hallmarks

One of the most simple ways to determine if a diamond is real in a piece of jewellery is to examine it for hallmarks.

These aren’t easy to see with the naked eye, but a lot of jewellery actually has some form of hallmark for diamonds along with the size.

What you’ll need:

1 x Loupe or magnification device

I personally never go anywhere without my loupe and if you haven’t got one already then its an invaluable, inexpensive piece of kit that could potentially make you money and save you money in the future.

  1. Take the item into a room with good light, or place under a desk light.
  2. Using your loupe carefully study the item, looking for hallmarks.
  3. If you see DIA stamped with for example 0.50 or another number next to it then congratulations your item is diamond.

Its worth noting though as with any jewellery that features a gemstone, its better to have it appraised by an expert.

Over time jewellery can be damaged and stones lost, leading to them being replaced with much cheaper or synthetic fake stones. So that diamond hallmark still isn’t gospel!

Diamond & Water Test

What you’ll need:

Glass of water


There’s really nothing complicated about this diamond test, its perhaps the most simple of them all.

Take a glass of water, drop the diamond in and watch what happens.

If the diamond floats, it’s not a diamond.

If it sinks this is a good indication that your diamond may well be authentic.

Heat Test

Before you carry out this test to see if your diamond is real you should be aware that if it isn’t a real diamond it could damage the stone. So do not carry this test out if the item has sentimental value.

What you will need:

Glass of cold water


Fill a glass with gold water.

Take your pliers and grip the diamond, with your other hand take the lighter and begin to heat the diamond.

Keep the flame from the lighter on the stone for approximately 40 – 50 seconds.

Drop the stone straight into the cold water.

If the stone cracks then it is not a diamond.

A real diamond is not effected by high temperatures and does not absorb the heat.

Testing A Diamond With UV Light

Again I reiterate that this test is not a guaranteed way of identifying a diamonds authenticity it’s more of a test that will need to be combined with other test to help you.

What you will need: 

UV Light device


In a dark room take your UV light device and place your diamond beneath it.

Analyze the glow from the diamond, is it blue in color?

Most diamonds will emit a blue glow when placed underneath a UV light, however not all diamonds will.

So if your diamond does not produce a blue glow then don’t panic it does not mean that you have a fake.

This is just another test you can carry out to help you determine if its real.

Reading a newspaper test

This test is usually used on loose diamonds opposed to one that is set in jewellery. You will need a good eye to determine the results.

What you will need: 



Place the loose diamond down onto a newspaper, flat side facing down. Ensure that the area you lay the diamond down on the newspaper has lots of small lettering below.

You’ll need to make sure there is adequate lighting in the room and nothing is obstructing the view with shadows.

Now look through the diamond, can you read the newspaper? If you can the diamond is 99% a fake, even if the lettering seems blurry.

If the diamond is authentic and real you will not be able to read the letters of the newspaper through it.

This is because the facets refract light in many directions.

Remember though when determining a diamond the best way is to take it to an expert and these simple tests do not guarantee you have a real or fake diamond.

Diamond dot test

As above with the newspaper test, this is a very similar test you can carry out if you don’t have a newspaper handy.

What you will need:

Plain White Paper


Take your pen and draw a dot on the plain white paper.

Now take your diamond and lay it down on top of the dot with the flat side of the diamond facing down.

Look directly down through the diamond, can you see the circular reflection of the dot through the diamond? If so there’s a large possibility that the diamond is not real.

If you can’t see the dot or a reflection then there’s a good possibility the diamond is real.

Again this test works on the basis that a diamond refracts light, the light bounces through the diamond in different directions so you will not be able to see the dot through it.

Sparkle test

What you will need:

Lamp or a light


Take your diamond and place it beneath a lamp or light, any will do.

Now focus on the diamond and take note of how the light reflects of the suspected diamond.

If it is real it should reflect bright white shimmers of light along with colored light reflections.

Authentic and real diamonds refract light, colored light and fire and will produce a sparkle unlike a fake.

When comparing the two, both a real and fake diamond, you will see a noticeable difference in sparkle.

Diamond Testing Device

Not immediately helpful I imagine if you don’t already own a diamond tester.

That being said, a diamond tester is one of the most accurate ways to test your stones authenticity.

I recently wrote a dedicated article all about the best diamond testers, how they work and how to use them.

If you’re testing quite regularly or want a more accurate way of testing diamonds then you can buy them for as little as $10, however like with anything buy cheap buy twice.

All of the above home diamond testing methods will help you determine whether you have a real diamond in your possession or a synthetic diamond.

If you’re going to be testing numerous diamonds in the future then we’ve wrote an article on diamond testers and detectors, you may well benefit from purchasing one.


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