Cubic zirconia and diamond may look similar because of their appearance and high refractive index, but in reality, they are not. The fact is, diamond is expensive and generally naturally occurring substance, whereas cubic zirconia (CZ) is human-made and a less expensive substitute for diamonds. In this guide, we will explore the primary differences between diamonds and cubic zirconia.

Lustro Stella cubic zirconia halo ring on white background.

Diamond or CZ? Follow this link to see if you’re right!


Diamonds can be found in both natural and synthetic forms. Mined diamonds are expensive, while synthetic ones are typically cheaper. They are lab-created diamonds, which are chemically, optically, and visually identical to mined ones. They are real diamonds, with the main exception being that they are created in a laboratory.

Cubic zirconia, just like synthetic diamonds, is also lab-created. However, they’re known as diamond simulants, meaning that apart from looking like a diamond, they have little else in common. For example, diamonds are made of carbon, whereas cubic zirconia is made of zirconium oxide.

One of the best things about cubic zirconia, as opposed to mined diamonds, is that they are a sustainable choice of gemstone, due to its lab created origin. You can be assured that the cubic zirconia is conflict-free, ethical, and durable.


Diamonds are the hardest naturally occurring mineral in the world, defining a perfect ten on the Mohs scale of hardness. They are incredibly durable and resilient, making them ideal for daily wear jewelry like engagement or wedding rings. Diamonds sustain their beauty and sparkle with minimal maintenance. They do not easily get scratched or chipped and are incredibly durable.

On the other hand, cubic zirconia ranks 8.0 to 8.5 on the Mohs scale of hardness. It is also a hard stone, but comparatively more easily scratched and damaged. Over time, cubic zircon can become cloudy and requires regular cleaning and care to restore its shine. You may also take the stone to a jeweler for occasional cleaning now and then, and eventually may even have to get it replaced.                                                                                                      

Bottom line?

Upkeep is an integral part of owning any piece of jewelry. When it comes to longevity and overall strength over time, diamonds performs much better than cubic zirconia.

Rhapsody diamond men's ring in platinum.

Can you guess if this ring is diamond or cubic zirconia?


Colorless diamonds are highly admired because of their rarity and beauty. Diamond color is graded on a scale from D (colorless) to Z (yellow), with D grade color being the most valuable. Often, better color will cost significantly more.

Because cubic zirconia is lab-created, manufacturers can control the final product to a large extent. These stones are almost always colorless, similar to the D grade of a diamond. Nearly every cubic zircon stone can have the stunning colorless look found in the best diamonds.

Colored diamonds such as red, pink, green, champagne, and blue are available but often beyond the budget of many buyers. Colored cubic zirconia, on the other hand, can be very affordable.


While purchasing a diamond, the clarity grade is a crucial factor that has a direct impact on the value of the stone. They come in different clarity grades, from Flawless to Included.

Flawless diamonds are the most expensive as they are highly sought after as they contain the fewest inclusions. Cubic zirconia has nearly impeccable clarity, which is almost always a dead giveawary for telling the difference between CZ and diamonds.

Flawless diamonds are incredibly rare and, thus, expensive. While some may regard cubic zirconia as flawless, they’re usually considered “too perfect” or “fake-looking” when compared to diamond. The truth is, cubic zirconia can also display eye visible inclusions like a diamond. However, most of this material hardly ever gets used in jewelry.

Floral diamond ring on white background.

Is this floral ring diamond or cubic zirconia?


One of the main reasons why anyone would prefer cubic zirconia over diamonds is the dramatic difference in price. The price per carat is vast between diamonds and CZ, so much so that the comparison even seems pointless. The price for one-carat cubic zirconia can be tens of dollars, whereas, the cost of an equivalent one-carat diamond could be several hundred, if not thousands of dollars! For this reason, cubic zircon is a popular option for those who want a large, dazzling stone without the associated price tag.

Diamond has a good market value which helps it remain valuable from generation to generation as an heirloom, whereas cubic zircon typically has no after-market value of its own.


The refractive index (RI) refers to the angle at which light enters a gemstone. As the light bends and is reflected, it creates brilliance within the stone.

Cubic zircon has a RI of 2.15 to 2.18, while diamond is higher at 2.42. Though both stones sparkle, a diamond has a greater depth of brilliance which a cubic zircon can never match.

Without uncertainty, a diamond’s brilliance is one of a kind, adding to its timeless allure.


CZ has a higher density than diamonds, meaning it is 1.7 times denser than diamond! This means that a diamond and a cubic zirconia of the same dimensions will not share the same carat weight. Cubic zirconia has a density ranging in 5.5 to 5.90 and diamond is 3.50 to 3.53, which means one carat of cubic zircon look smaller than a carat of diamond when all other factors are equal.

A gemologist or jeweler can easily differentiate a CZ stone from a diamond by weighing it on their scale.

Lustro Stella cubic zirconia ring.

Is this ring diamond or CZ? Click to find out!

Light Dispersion

Depending on the design of your jewelry, you might want a stone with a higher degree of fire or brilliance. Dispersion is determined by how light passes through the gem, and there is a sharp difference between CZ and diamond. Diamonds are more brilliant, whereas cubic zirconia is often more sparkly and dazzling. Also, they produce much more colored light than diamond.

Diamonds have a dispersion rate of 0.044, while cubic zirconia has a higher level of dispersion, at 0.066. This factor means that cubic zirconia displays a pronounced ‘rainbow effect’ when light passes through it. It is yet another tell-tale distinction between diamonds and cubic zirconia.

Although it is hardly distinguishable in smaller stones, this heightened dispersion in cubic zircon is extremely noticeable when its carat size increases.

Which Is Better – Cubic Zirconia or Diamond?

Diamond and cubic zirconia share a few key characteristics but vary significantly in terms of quality, price, and longevity. For a piece that can withstand generations of use without much maintenance, diamond is the clear winner. However, if you’re looking for an affordable stone that’s still shiny, beautiful, and timeless, then cubic zirconia might be the better choice. The amount of care, time, or money that you want to put into your jewelry can be an excellent way to determine what you need!

What Sets Lustro Stella Jewelry Apart?

High in style and reasonable in price, Lustro Stella jewelry is hard to resist. Drawing inspiration from current diamond trends, these jewelry pieces are admired for their modern, elegant, and durable designs. Featuring high-quality AAAA grade cubic zirconia, every jewelry piece is crafted from brilliantly polished 925 sterling silver.

Discover incredibly priced Lustro Stella rings, earrings, necklace, bracelet at Shop LC, and make an impressive addition to your jewelry collection.

The Verdict

Before choosing a stone for your jewelry, consider your expectations and budget. The differences are might not seem significant, but choosing between a diamond and cubic zirconia stone can completely transform your jewelry.

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Would you choose a diamond or a cubic zirconia? Tell us in the comments below!


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