How to Tell If a Diamond Is Real — Identifying Fake Diamonds

Fake diamonds get more convincing every year.

How Do You Tell If a Diamond Is Real?

You just inherited a beautiful ring. There's only one question: Is it a real diamond? Today, fake diamonds can be very convincing. And there's a difference between lab-created diamonds and natural diamonds, too.

Knowing whether you're holding "real diamond jewelry" matters, both in terms of value and care. Diamonds remain one of the most expensive and most prized gems. Here's everything you need to know about diamonds.

How to Tell Whether a Diamond Is Real

How to Tell If a Diamond Is Real By Its Appearance

Take a good look at your diamond. There are a few ways you can tell whether a diamond is real just by its appearance:

Is it hazy or does it have air bubbles? Air bubbles are a sure sign of "paste" (resin). A diamond can be occluded (have other material in it), but it's very rare to use this type of diamond in jewelry unless it's an antique.
Does it seem a little too shiny? A real diamond is brilliant, but not distracting. It glows white, not rainbow. If you have something that's very shiny, it's probably cubic zirconia (CZ) or moissanite.
Is it too perfect? If the diamond is flawless, it could actually be either fake or lab-created. There are some imperfections in most natural diamonds, especially antique diamonds.
Does it fog? If you breathe on the diamond, a fog should not appear for more than a few seconds. If the fog lasts, it's not a diamond.
Will it cut glass? While this isn't a definitive test (and contrary to popular belief, it can injure a diamond if done the wrong way), cutting glass does indicate the presence of a real diamond.

But you don't need to test your diamond by its appearance alone. There there are actually tools that you can use to determine whether a diamond is real. This is usually what pawnshops will do.

How to Test a Diamond to Determine Whether It's Real

A diamond tester can be purchased for less than $20. Diamond testers work by measuring the conductivity of the stone. Real diamonds are excellent conductors, whereas fakes are not.

To test a diamond:

Turn on the tester and touch the tip to the stone.
If it's a real diamond, the tester will light up green and make a beeping sound.
If it's fake, the tester will light up red and make a buzzing sound.

You can also use a refractometer to test whether your diamond is real. A refractometer uses light to determine the diamond's dispersion (the "fire" in a diamond). But a refractometer is a more expensive, specialized tool.

To use a refractometer:

Hold the diamond between your thumb and first finger.
Look through the eyepiece while shining a light on the stone.
If it's a real diamond, you'll see a double image of the needle in the refractometer.
If it's fake, you'll only see one image.

How to Determine Whether a Diamond Is Real by Its Setting

The setting of a piece of jewelry can also give you some clues about whether the diamond is real.

Bezel settings are difficult to do with fake stones because they require a very precise cut. So if you see a bezel setting, that's a good sign that the diamond is real. Pavé settings are also difficult to do with fake stones because they require tiny stones to be set very close together.

On the other hand, claw settings are fairly easy to do with fake stones, because the claws can cover up some of the imperfections. If you see a claw setting, that doesn't necessarily mean the diamond is fake, but it is a potential indicator.

Another thing to consider is the metal in the setting. If it's real gold, that's a good sign. If it's silver, it may not be real diamonds.

How to Tell Whether a Diamond Is Real By Provenance

If you're buying a diamond from a reputable jeweler, they should be able to tell you the provenance of the diamond. Provenance is basically the origin story of the diamond, and it can tell you a lot about whether the diamond is real.

For example, if the seller can tell you that the diamond was mined in a specific region, that's a good sign. If they can't tell you where the diamond was mined, that's a potential red flag, not just for whether it's real or not, but whether it's conflict-free.

The provenance of a diamond can also tell you whether the diamond has been treated in any way. For example, some diamonds are irradiated to improve their color. That makes them beautiful but less rare than a natural diamond.

How to Identify a Lab Diamond vs. a Natural Diamond

If you're not sure whether a diamond is real or fake, it might be a lab-grown diamond. Lab diamonds are real diamonds, but they're made in a laboratory rather than mined from the earth.

The best way to tell if a diamond is lab-grown is to look for an inscription on the stone. Many lab-grown diamonds will have an inscription on the stone, but you may need a jeweler to see it.

How to Determine Whether a Diamond Is Conflict-Free

If you're concerned about whether the diamond is conflict-free, there are a few things to look for.

The best way to tell if a diamond is conflict-free is to ask for the Kimberley Process Certificate. The Kimberley Process is an international system that tracks diamonds from their origin to ensure they're not from a conflict zone.

You can also look for the " responsible sourcing" label from the Jewelers of America. This label means that the diamond has been sourced from a country that is part of the Kimberley Process.

How a Jeweler Can Tell If a Diamond is Real

A jeweler will be able to tell if a diamond is real by looking at it under a loupe, which is a magnifying glass. A jeweler will also look at the stone's weight, clarity and cut.

Perfect diamonds are very rare, so if the stone is flawless and has no inclusions, it's likely lab-grown. If the stone is cut poorly, it's also likely a fake. Real diamonds are cut to precise standards that maximize their brilliance and fire.

Finally, a jeweler will look at the setting to see if it's been done properly. If the setting is poorly done, it's a sign that the stone is probably not real.

Types of Fake Diamonds

The most common type of fake diamond is cubic zirconia. Cubic zirconia is a man-made stone that looks very similar to a diamond. It's made of zirconium dioxide and comes in a variety of colors.

Cubic zirconia is far less expensive than a real diamond. It's also somewhat "flashier" and often its flashes will have a bit of a rainbow to them.

The best way to tell the difference is by looking at the stone under a microscope. Cubic zirconia will have flat facets, while diamonds will have rounded facets. Cubic zirconia is usually used in "fashion jewelry" rather than precious jewelry.

Another type of fake diamond is moissanite. Moissanite is a silicon carbide that is used as a cheaper alternative to diamonds. Moissanite will be much flashier than a diamond, much like cubic zirconia. Today, moissanite is frequently used as a diamond replacement, so it may be used in fairly expensive settings.

Finally, there are glass stones that are made to look like diamonds. These are the least expensive type of fake diamond, but they're also the easiest to spot — they have almost no refraction, just like glass.

Why Are Diamonds So Expensive, Anyway?

People wouldn't make fake diamonds if there weren't money in them. Have you ever wondered why diamonds are so expensive?

There are more reasons than you might think — including some surprising ones.