Cubic Zirconia vs Diamond: How to Spot the Difference

Cubic zirconia costs just over 1% of what an equivalent diamond would. CZ has earned great popularity for its similarity to a diamond without the cost. Casual observers can't tell the difference between a simulated diamond and a genuine article.

If you're here, though, you want to know how to separate the real thing from the competitors. Just what makes an artificial diamond artificial?

We'll walk you through some of the most common methods for detecting the real deal.


Cubic zirconia has a lower hardness than diamond. As a result, the wear and tear of daily life will affect it much more readily than the more expensive stone. That's not to say every little thing will scratch a piece of cubic zirconia office jewelry, but things can and will do so.

These tiny scratches can leave cubic zirconia looking cloudy, even if no individual scratch leaves a major mark. This can help you identify older pieces, though factory-new cubic zirconia will retain clarity.

The Natural Light Test

One way you can separate an artificial diamond from the real deal focuses on holding it up under natural light. In the rays of the sun, a diamond will take on a brilliant white shade, while CZ will present a more dazzling array of colors. This happens because of the physical properties of CZ, such as its lower refraction and higher dispersion.

The facets of both stones can give off colors when held up to the light, especially when held up upside down. A diamond will present a full rainbow, whereas cubic zirconia will tend to have a blue and orange shine specifically.

Weight and Feel

If you have a scale or a similar piece of jewelry, the weight will always tell the story. Cubic zirconia weighs more than diamond, coming in at half again as much as the genuine article.

The lower weight and better thermal conductivity also make a diamond warm up in your hands faster. If the stone takes a long time to pick up the warmth of your hands, it's more likely to be CZ.

Can You Test Cubic Zirconia with a Scratch?

Common wisdom for testing an artificial diamond involves the scratch test, which relies on the Mohs hardness scale. All you would need to do is push the suspicious gem against a mirror or a pane of glass and drag. A real diamond can cut anything and will leave a scratch, while the fake slides harmlessly along.

This doesn't work for zirconia. The "American diamond" has a lower overall hardness than the real thing, but it still beats out a glass mirror. The glass test can disqualify other artificial diamond products, but not CZ.

Know What You're Getting

Even if cubic zirconia stones aren't real diamonds, they can still complete a look. You should always know exactly what you're purchasing and avoid getting scammed. 

If you're looking for your next piece of jewelry, contact us or take a look at our site. We have a wide range of pieces to suit any price range and any look.