How can you tell if a diamond is real?

This post was sourced from submitted reader questions and posted by wikiHow Editorial Staff, based on our article: How to Tell if a Diamond is Real .

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wikiHow Editorial Team

04/09/25 6:39pm

There are various techniques you can use to tell if a diamond is real.

Water Test: Place a few drops of water on your diamond. The water will float on top of a real diamond, but sink into a fake one.
Fog Test: Breathe on the diamond to fog it up. If it stays fogged for a couple seconds, it's probably fake, but if it doesn't fog up easily, it may be real! That's because real diamonds disperse heat from your breath instantaneously.
Mount and Setting Quality: Real diamonds are likely to be set in quality materials. Check for stamps that indicate real gold or platinum (10K, 14K, 18K, 585, 750, 900, 950, PT, Plat). "C.Z." stamps give away that the center stone is Cubic Zirconia, which is a kind of synthetic diamond.
Newspaper Test: Turn the diamond upside down on a piece of newspaper or text. A real diamond bends the light so sharply that you can't see the print through it.
Dot Test: Draw a small, dark dot on a piece of white paper and place the diamond over the center of it. If the diamond is real, you shouldn't be able to see the dot through it.
Reflection Color: A real diamond's reflections should be intense and in shades of gray. They should not be rainbow reflections.
Float Test: A real diamond sinks in a glass of water because diamonds have a high density.
Shatter Test: Heat up your diamond with a lighter for 30 seconds, then drop it in a glass of water. A fake diamond will shatter, while nothing should happen to a real diamond.

How are you able to tell if a diamond is real? Let us know in the comments below!

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Joseph R. Villarreal, G.G. (GIA)
Jeweler

06/19/25 7:46pm

Here are a few ways to tell if a diamond is real.

1) Breathe on the stone - if it appears to be misty for a few seconds, then it is most likely not a real diamond.
2) Water test - Drop the stone into a cup or glass of water, if it sinks rapidly, then there is a very high probability the stone is diamond. Other simulated stones may float or linger.
3) Reading test - Place the flat side of the stone on or over the small writing from some text in a book or magazine. If you can read the letters through the stone then it is likely NOT diamond.

A more definitive way to differentiate diamonds from other simulated stones is to take the stone to your local jewelry professional. A trusted jeweler with the credentials of a Graduate Gemologist (GIA) will be able to provide you with a conclusive answer whether the stone is diamond or not.

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