How to recognize a fake diamond?


Among our family jewels, we may be hesitant about the authenticity of one of them or want to reassure ourselves about a diamond we have just acquired. There are several ways to verify the authenticity of a diamond, many of which can be done at home, without the specific equipment, advice or expertise of a gemologist. This section offers you some simple and reliable techniques that will allow you to know if your diamond is real or fake.

Using a glass object

Rub the tip of your diamond on a glass object that you no longer need. If the diamond leaves a mark or scratches the glass, it is most likely real. 

The transparency test

A real diamond reflects light, which means that it is impossible to see through it. Take a newspaper page, a book, or any piece of paper with writing on it. Place your diamond flat on the text and try to read through it. If you can make out any letters, your diamond is most likely a fake. A real diamond would not allow you to read any letter. In this case, it could be a piece of glass, zirconium, or other worthless material.

Looking with a magnifying glass or microscope 

You can also take a close look at your diamond with a magnifying glass or microscope, if you have one. A real diamond has no scratches and has very sharp edges. The presence of any scratches or rounded edges should alert you to the fact that it is probably a fake.

Using a glass of water

Fill a glass with water and dip your diamond in it. If it floats, it is most likely a fake. Real diamonds sink and do not float on the surface of the water.

Fogging it up

Breathe on your diamond. If it fogs up, it is likely a fake. The effect of condensation on a real diamond does not fog up, because real diamonds radiate heat.


The X-ray machine is a tool that is not easily accessible for a private individual, but is very convincing. If, however, you have the possibility, do not hesitate to test your diamond by this means. If it is real, it should not appear on an X-ray, because diamonds have a radio-transparent molecular structure.

Ask a jeweler or a diamantaire

For a quick and safe certification, jewelers and diamond dealers remain the best way of verifying the authenticity of your diamond. Do not hesitate to ask them for an expertise on your stone. They should be able to quickly and easily confirm the authenticity of your diamond.