How To Tell Cubic Zirconia From Diamond?

How To Tell Cubic Zirconia From Diamond?

It's important to be aware of the numerous fakes out there if you're in the market for a new diamond. Cubic zirconia, a man-made gemstone, is the most popular method of selling phony stones to naive customers.

Diamond stimulants have existed for years. CZ, or Synthetic Cubic Zirconia, is one of the newest and most popular. A casual observer might mistake them for diamonds. However, a few simple tests will reveal that they are not real diamonds at all. One of the first steps in the lab grading process is to screen certified diamonds for simulants and synthetics using sophisticated instruments.

A few telltale signals jewelers may utilize to assist in distinguishing between diamonds and cubic zirconia when inspected attentively.

Cubic Zirconia

How To Identify Cubic Zirconia

For the inexperienced, the following tests can be used to distinguish between CZs and diamonds:

The Weight Test

Unlike diamond, which is made out of carbon, cubic zirconia (CZ) is built of crystals, making a significant difference in the composition. Cubic Zirconia (CZ) weighs 2.6g/cm3, whereas diamond weighs 3.52g/cm3. Cubic Zirconia is less dense than diamond because of this. CZs weigh about 1.7 times as much as diamonds of the same size if they are not set in jewelry. Therefore, they can be easily identified by weighing them. A 6.5 mm round diamond, for example, will weigh about 1 carat. The carat weight of a CZ of this size is approximately 1.70.

Price Test

In order to determine a diamond's value, the most important considerations are its size and quality. Natural diamonds are more expensive and have more attractive inclusions. On the other hand, CZ stones are less expensive. Weight, color, clarity, and cut all play a role in determining a diamond's final price. Because of their weight and lack of clarity, CZ stones are less expensive than diamonds.

Color Test

Diamonds are enjoying a rebirth in popularity because of programs like 'Devious Maids,' which feature them prominently. You can find diamonds in 750-800 distinct hues. IT IS NOT AS POPULAR because CZ is colorless and does not sparkle as much as diamonds. Choosing a colorless diamond over a CZ stone is a better option since many more appealing diamond hues exist.

The newsprint test

The stone must also be loose for this test to work. Place the stone on a newspaper or magazine page and turn it over. You won't be able to see the letters clearly because of the high refractive index of diamond (it bends light more than CZ). However, with a CZ, you can see some of the print.

Fog Test

CZs remain foggy for several seconds after breathing on them. In contrast, the diamond fog dissipates almost immediately after the same procedure. This is because a diamond has a higher thermal conductivity than other materials.

Shape Test

Critical properties used to determine the quality of a diamond. This includes color, clarity, carat, and weight.  Angles and the brightness of light reflected from the diamond's surface are used to calculate carat weight and carat size. A diamond's superior cut is due to the stone's facets, which are perfectly oriented and proportioned, shaping up to reflect light better. Rather than a perfect cut, a domed octahedron characterizes cubic zirconia's form.

Clarity Test

The number of faults visible at a magnification of 10x determines a stone's clarity. The clarity of the diamond ranges from flawless to a CZ-like clarity. 'Flimsy,' on the other hand, is the polar opposite of transparency. When diamonds are cut from the same facets, this problem is more likely to arise. Thus, the diamond's cut also can make it seem 'flimsy.'

Additional Signs You Might Have A Diamond

In addition to the above, there are many more indicators that a stone is a CZ or other simulant:

  • Gold plating or silver settings are very unlikely to contain genuine diamonds. A precious metal setting will have a stamp-like 14K, 18K, or PLAT. Remember, CZ may be set in almost any metal. Thus, this is only indicative.
  • There's a reasonable probability it's not a genuine diamond if the stone has no apparent inclusions and is entirely colorless. Even if this were true, there would still be some doubt since some actual diamonds may be colorless and flawless.
  • If the facet joints are somewhat rounded or the stone has any evident abrasions, it is very unlikely to be a diamond under magnification. Despite the diamond's great hardness, which allows for exact faceting, it is unlikely to be severely scratched or scuffed during use.

However, if you're still unsure, take the stone to a trusted jeweler for an inspection. Simulant CZs may be promptly identified by jewelers using simple electrical testers. A certified gemologist can only perform the examinations required to make the most critical differences. They may also help you if the stone requires further testing or grading in the laboratory.


There's a good reason why natural diamonds are the king of the stones. They're one-of-a-kind, which makes them gorgeous and priceless. Natural diamonds are rare and costly to mine and cut. Thus, they have a long-term worth. Cut, color, clarity, and carat weight contribute to the diamond's value. Are you purchasing a genuine diamond? Check out our buying guides for some pointers on what to look for.

 Work with a reputable company when you're looking for diamonds. By offering both lab-grown diamonds and natural diamonds, Luvari is dedicated to meeting the needs of its customers.

Please make an appointment to speak with our team members about diamond products. Contact us and start your search for a real diamond Jewelry today with our help!

Shop Our Wedding Bands