How to Tell a Cubic Zirconia From a Diamond Quickly

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Diamonds and cubic zirconia have been around for a long time, and they are very popular stones for making all sorts of jewelry. The truth is, telling the two apart can be somewhat difficult, especially if you do not have much experience with either.

As much as they bear a striking resemblance, they both have unique characteristics that set them apart, and that can help you identify which of the stones you are handling.

In this article, we are going to explore the details of each stone and the features that distinguish them, as well as a couple of tips on how to tell them apart, even when you are not experienced or a precious and semi-precious stone expert.


Can the average person tell the difference between Cubic Zirconia and Diamonds?

Two features of cubic zirconia and diamond make them easy to confuse; their clarity, and their ability to sparkle.

It becomes even more confusing because the two stones oftentimes feature similar cuts, thanks to the kind of jewelry in which they are featured.

The short answer is no, an average person cannot be able to tell the difference between cubic zirconia and diamonds by just looking at them.

There are a few distinguishable differences between them but in many instances, cubic zirconia is confused for diamonds, and diamonds are mistaken for cubic zirconia.

However, one simple trick has been used to tell the two apart over time, and it has everything to do with how each stone reflects and refracts light.

When placed under natural light, cubic zirconia gives off a rainbow-like reflection that is accompanied by many colors. Diamonds, on the other hand, give off a white light that is brilliant, and that does not bear any other colors. This is the simplest and quickest way of telling the two stones apart.

So, what are the main elements of cubic zirconia and diamonds?


What is Cubic Zirconia?

Cubic zirconia is a man-made semi-precious gemstone.  It is made of crystalline zirconium ii oxide and is almost always produced in a laboratory setting.

There have been several uncovered deposits in nature, but most were too small and have since been depleted. Seeing as it has become incredibly popular, it is now produced in controlled settings to meet the growing demand.

Cubic zirconia, as earlier mentioned, closely resembles diamonds, and this characteristic has earned it the name diamond simulant.

Even though it is a lab-produced compound, cubic zirconia is a heavy and dense stone. It has a density of between 5.6 and 6.0 g/cm3, making it 1.6 times denser than diamonds.

It is, however, not as hard as diamond, but it is relatively harder than most other natural semi-precious stones.

Because of its close resemblance to diamonds, cubic zirconia is used as a cheaper alternative to precious stones, especially diamonds.

Diamonds can be very expensive, and this is why cubic zirconia makes a welcome alternative.

How to Tell a Cubic Zirconia From a Diamond

Over the years, many manufacturers have resorted to various ways of improving the overall quality and aesthetic of cubic zirconia.

One of the most common ways of doing this is by coating the semi-precious stone with DLC (diamond-like carbon) through a process called chemical vapor deposition. This process makes cubic zirconia more lustrous and stronger and makes it resemble a diamond even more closely.   

When it comes to application, cubic zirconia is used in making jewelry such as rings, bracelets, earrings, necklaces, watches, and many others.

The semi-precious stone is also used to make lenses, windows, filters, prisms, and laser elements. It has even, on multiple occasions, been used to make extremely sharp scalpels used for operating on bio-tissues as they require a smoother edge than steel.


What is a Diamond?

Diamond is a naturally occurring precious stone that is quite rare. It is made of carbon and is formed when extremely high pressure and intense heat combine beneath the earth’s surface, causing carbon molecules to form strong bonds.

Due to the high pressure and heat under which diamonds are made, they become very strong and are, in fact, the hardest substance known to man.

In recent years, the demand for diamonds has seen a significant increase, and for this reason, a lot of it is produced in laboratories.

The process is well controlled, and you cannot be able to tell a naturally occurring diamond from one produced in a lab. However, lab diamonds can be much cheaper, ranging from 10% to 40% less expensive than earth mined gemstones.

One of the reasons why diamonds are considered very beautiful is the way in which they interact with light. They have a high refractive index, and they are able to bounce off tones of light when it passes through them.

This characteristic is one of the main reasons why it is considered extremely beautiful, and also why it is one of the most sought-after precious stones in the world.

Even though diamond is considered the hardest substance on earth, it is prone to damage in various ways. It can acquire scratches from other diamonds, and softer materials such as vinyl.

However, it is highly resistant to damage and can maintain its luster for decades, and this characteristic is one of the reasons why it is a very expensive and highly coveted mineral.

Seeing as it is a naturally occurring substance, a diamond may oftentimes come with a hint of color. There are some that exhibit a brown hue, and others a yellow one.

There are also pink, blue, and clear diamonds, and the prices for all of them vary. The purest form of diamond appears completely clear and is free of any hints of color.

Because of its beauty and hardness, diamond is a very versatile gemstone that is used to make precious jewelry and in many industrial activities such as cutting other hard substances.

Over the years, diamonds have been used to make some of the most precious and most expensive pieces of jewelry all over the world, and they remain coveted objects, especially for many a jewelry enthusiast.


Cubic Zirconia vs. Diamonds – 8 Main Differences

1. Color Difference

Being that cubic zirconia is almost always produced in a lab setting, its manufacturers have the liberty to choose whichever color they prefer for it.

However, since it is largely meant to compete with diamonds as a simulant, it is made without color. On the off chance that you are going to come across colored cubic zirconia, you may not be able to find a coloring system for it since colored cubic zirconia is quite rare.

Diamonds, on the other hand, come with an elaborate coloring system. As earlier mentioned, naturally occurring diamonds may come in multiple colors. Since the color of a diamond determines, in a large way, how much it is worth, it is necessary to grade them according to a detailed color scheme.

The coloring scale starts at D and goes all the way to Z. D diamonds are the clearest and are ranked highest in value while Z diamonds have the most color and are ranked lowest in value.

Z diamonds are yellow in color, and even the intensity of yellow varies from gemstone to gemstone. Below is a tabulated representation.


Scale Color
D, E, FClear (colorless)
G, H, I, JNearly colorless
K, L, MFaint yellow
N, O, P, Q, RVery light yellow
S, T, U, V, W, X, Y, ZLight yellow


When it comes to the overall value of diamonds, less color means more value while more color reduces the worth of the gemstone.


2. Clarity

Since most cubic zirconia produced is made in laboratories that have controlled environments, it is easy to determine what the resulting stone will look like.

For this reason, cubic zirconia tends to have the highest degree of clarity. As a result, jewelry that is made from this semi-precious stone is flashier, especially when you wear it out in the sun or in a brightly lit room.

Diamonds, on the other hand, are a naturally occurring substance, a feature that makes determining the clarity of each stone difficult.

Because of this, there is a clarity grade for diamonds, and how each stone is graded determines its value. When diamonds are mixed with other elements, they are described as flawed.

The lowest grade of clarity for diamonds is called Included, while the highest and most expensive is referred to as Flawless.


3. Brilliance/ Refractive Index

This characteristic refers to how bright cubic zirconia and diamonds are. It does not have anything to do with the stones’ color or clarity but denotes how deep or pronounced their sparkle is.

How to Tell a Cubic Zirconia From a Diamond

When placed under natural light, diamonds have a deeper sparkle than cubic zirconia. Diamonds have the second-highest refractive index of all gemstones in the world after moissanite, presenting a refractive index of n2.42.

Cubic zirconia does not fall too far behind though and has a refractive index of n2.16. This means that you will still get a nice sparkle from the semi-precious stone, but diamonds will definitely steal the show if they are featured together.


4. Price

Cubic zirconia is a very affordable gemstone and a piece of 1 carat will cost about $20. (factory price is about$ 1) With a diamond, however, you will have to spend significantly more, with 1 carat of the same costing up to $10,000.

Simply put, if you want to upgrade a $200 piece of jewelry that has 10-carat cubic zirconia so that you end up with one that has a 10-carat diamond, you may have to spend in excess of 500 times the original amount.

Diamond, apart from its beauty, has many more desirable characteristics such as durability which make it that much more expensive than cubic zirconia.


5. Dispersion

Even though this characteristic has everything to do with light, it is completely different from brilliance (refractive index).

Dispersion refers to how the stones allow light to go through them and how the light is perceived by the eyes of the viewer once it exits the gemstone.

How to Tell a Cubic Zirconia From a Diamond

One of the features that determine the dispersion is the facelets of gemstones. The facelets are defined by the specific cut used on the stone.

When the light goes through cubic zirconia, it is split into the colors of the rainbow so that your eyes can see all those colors. This phenomenon is called the ‘fire effect’ and it is more pronounced in cubic zirconia which has a dispersion rate of 0.05 to 0.06.

With diamonds, the light is not split into the colors of the rainbow, making it less dramatic than cubic zirconia. On average, diamonds have a dispersion rate of 0.04, setting them slightly behind cubic zirconia.


6. Durability

As earlier mentioned, diamonds are the hardest substance on the surface of the earth and, for this reason, they are able to last very long without significant wear and tear.

In storage, however, diamond is its own worst enemy. Pieces of jewelry that contain diamonds can rub against each other and cause scratches. This is why they should be stored apart from each other or wrapped in smooth clothing to keep them damage-free.

Cubic zirconia, on the other hand, is a slightly weaker material than diamond. For this reason, it scratches more easily and is prone to faster damage than diamonds.

It is, however, quite strong and can last a very long time with its luster and without acquiring scratches that are easy to spot.  

How to Tell a Cubic Zirconia From a Diamond

7. Density

Even though cubic zirconia is not as hard a material as diamonds, it is a denser substance. This means that cubic zirconia is heavier than diamonds when it comes to weight.

To put this into perspective, if you have a piece of 1-carat cubic zirconia and a piece of a 1-carat diamond, the civic zirconia is going to be smaller in terms of size than the diamond.

For this reason, if you are looking to get a cubic zirconia ring or necklace, be sure to increase the carats to get a sizable piece that will be easier to spot. Seeing as diamonds are lighter, fewer carats give you a bigger gemstone when compared to cubic zirconia.


8. Edges

Diamonds feature cleaner and sharper edges where they are cut. The little facets have very precise cuts that are free of chipping and scrapes.

When you look closely at diamonds, you will see that they have pristine edges right from the top to the bottom.  

Cubic zirconia comes with rounded edges around the facets, but they are also quite clean, and you may have a hard time spotting chipping on the edge of a cut.


How can you tell cubic zirconia from a diamond?

How to Tell a Cubic Zirconia From a Diamond

One of the easiest and surest ways of telling cubic zirconia and a diamond apart is by using the dispersion method.

Observe the stone under natural light, and if you can see multiple colors on it, you will know it is cubic zirconia.

If, however, the light emitted is bright but does not have the rainbow colors, you will know it is a real diamond.



To a lot of people, having genuine diamonds is very important, and they could not settle for less even if they wanted to.

For others, however, funds may not support their expensive tastes, and they end up getting simulants like cubic zirconia.

Its resemblance to diamonds makes it an excellent fit and allows people to step out confidently.

If you are looking to purchase real diamonds, however, be sure to subject them to close scrutiny to avoid getting duped.

Read more useful tips here or here

Hey! I finally find the Answer!