Lab Diamond vs Cubic Zirconia (Which Is Better?)

Last Updated on January 9, 2023 by Juli "Jewels" Church

Looking for an in-depth comparison between lab created diamonds and cubic zirconia diamonds?

Perfect, you're in the right place! In this Learning Jewelry guide, you'll learn:

  • How does a lab grown diamond compare to a cubic zirconia diamond?
  • What're the differences in appearance between a lab diamond and cz diamond?
  • How do the prices compare between cubic zirconia and lab created diamonds?
  • And much more!
lab diamond vs cubic zirconia diamond

At first glance, someone might not be able to tell the difference between a cubic zirconia and a lab diamond, or even a real diamond. The only difference they might see is lower prices, which are evident if you take a quick look at the popular online diamond retailers.

But the truth it, the two have major differences including chemical composition and crystal structure, return of light and dispersion, and other optical properties.

Read Also: What're the top online stores to buy lab created diamonds?

Lab Diamond vs Cubic Zirconia: Origin

Even though both cubic zirconia and lab created diamonds are man-made material, only one of them can be considered "real". These two stones go through very difference processes to become what you see at a jewelry store. 

Cubic Zirconia 

Cubic zirconia is a diamond simulant or diamond alternative that goes by many names. Online, you can see it referred to as cultured diamonds, simulated diamonds, or man-made diamonds. Simulated diamond is the proper term for it. Only pearls are cultured and man made diamonds are a better term for lab grown diamonds. 

Natural cubic zirconia is super rare. So, they've synthesized it. Cubic zirconia is the product of powdered zirconium oxide melted with calcium and magnesium. The combination of the mixture is then cooled for some time, creating the crystals. Then, like the lab diamond, they are faceted and polished. 

There's not a set standard as to how cubic zirconia has to do it made, so you can find that different places that produce it may do it slightly different than others. 

Lab Diamonds

Lab diamonds are also called lab created diamonds, lab grown diamonds, or synthetic diamonds. 

Lab diamonds are made 1 of 2 ways, or even 2 of 2 ways. I'll explain. One method is called high pressure high temperature (HPHT). In this method, they take a tiny piece of a diamond called a diamond seed. It's then taken and put under copious amounts of pressure and heat. Gemologists then take that diamond seed and put into pure carbon and grown into a diamond. 

In the chemical vapor deposition method (CVD), the diamond see is put into a gas chamber. In many cases, the diamond seed has already gone through HPHT. The chamber is then filled with methane gas, or carbon gases. It converts into a plasma. That plasma breaks down molecules that had been bonded together, leaving nothing but carbon atoms left. That carbon forms around the diamond seed and crystalizes, on its way to becoming a diamond.

Read Also: What are the best fake diamond stud earrings?

Lab Diamond vs Cubic Zirconia: Appearance

When it comes to appearance, most people in jewelry can tell the difference between a cubic zirconia and lab (or natural) diamonds.

Jewelry buyers will notice the differences when pointed out to them. The light performance between the two is very different. 

Cubic zirconia displays what's referred to as rainbow light. This effect is glaringly obvious when placed next to a lab diamond. This overly flashy rainbow light is very dramatic, while a natural or lab diamond is more of a subtle brilliance.

Below is a video of lab diamonds and cubic zirconia diamonds side by side.

Natural and lab diamonds have inclusions, which are little bits of material stuck in the diamond as it forms. In lab diamonds, inclusions are metallic. Inclusions are considered identifying marks for the diamond.

A diamond's clarity is based on how many and which kinds of inclusions it contains. The higher the clarity grade, the less inclusions you'll be and that pricier the diamond will be. 

Cubic zirconia gemstones don't have any kind of inclusions or blemishes, so they appear flawless. They don't have any kind of grading system either, but you'll probably run into some being described as carat weight instead of millimeter size.

Lab Diamond vs Cubic Zirconia: Pricing

One of the biggest factors people considered when purchasing a product is the pricing. Everybody loves to save money, right? But, keep in mind, being "low cost" doesn't guarantee a better product. 

With cubic zirconia, we know this to be true. Cubic zirconia stones are very inexpensive. The can range from as little as $5 up to a few hundred. You shouldn't ever see a cz end up in the $1000 price range, unless it's set in precious metals or other valuable stones. 

The main reasons why cubic zirconia is so cheap is because it doesn't last long. In some products, you can find very affordable and high quality products. When it comes to jewelry, much of it is you get what you pay for.

Cubic zirconia is much easier to make and they can keep on making it. Lab diamonds can only be made for as long as we're able to get diamond seeds from natural diamonds. That's not to say that lab diamonds will stop being made, but it could happen eventually. 

Read Also: Are lab grown diamonds good or bad?

It also just doesn't hold up well to lab diamonds. Cubic zirconia cost isn't changed by the same factors that lab diamonds are. CZ doesn't have classes or tiers, nor do they follow a set of quality guidelines like lab diamonds do. The price of a lab diamond can increase drastically when you venture into higher grades such as VVS1 clarity, E color grades, and ideal cut diamonds. A vvs diamond price for example, will always be higher than your average clarity diamond.

You can purchase a low quality diamonds for thousands of dollars. With cubic zirconia, the quality depends on the manufacturer. With lab diamonds, much of it is up to chance, and the better ones are even higher priced. 

In most of cubic zirconia fine jewelry, it is the metal used that retains most of the cost. Cubic zirconia fine jewelry is usually set in sterling silver. 

Best quality cubic zirconia is set in 14K gold and still costs less than $1000. This 2 carat emerald cut cz from Birkat Elyon with side baguettes cost $670. 

Lab created diamonds are much more expensive than cubic zirconia. In addition, they are usually set in more precious metals than sterling silver, like gold and platinum.

Now, a 2 carat emerald lab diamond with nice diamond grades costs thousands more than a cubic zirconia ring, even if it is set in gold. A 2 carat lab grown diamond with a clarity grade of VS1 and a color grade of H costs a little over $12,000.

Lab Diamond vs Cubic Zirconia: Value

Obviously, there's a massive difference in price between both lab diamonds and cubic zirconia. Cubic zirconia holds no real value as a stone, even if you did buy a high quality one. Jewelers won't buy back even the highest the priciest cz. 

Most jewelers that do sell a small amount of cz stones won't offer any kind of protection either. Cubic zirconia jewelry bought at Zales doesn't come with any type of warranty, unless it's part of personalized jewelry. 

Even though lab grown diamonds are real diamonds, they don't hold the same value as mined diamonds. Many retailers that sell mined diamonds offer some sort of upgrade or trade-in policy. They always exclude lab diamonds in the fine print. 

The reason why is because the value of lab created diamonds is constantly fluctuating. They started off as being around 20% cheaper than buying a natural diamond, they can reach up to and even more than 50% cheaper now. If a jewelry store made an upgrade policy, they'd most likely take a loss and we know they don't want to that.

Lab Diamond vs Cubic Zirconia: Other Factors

There are other reasons why someone might prefer a lab diamond to a cubic zirconia, or vice versa. Here's some additional facts to consider. 


All minerals fall somewhere on the mineral scale of hardness, also known as the Mohs scale. Mineral hardness is how resistant the stone is to scratches and everyday damage. Hardness isn't the same as gemstone tenacity. A lab diamond may not able to be scratched, but it can shatter when smashed. 

Lab diamonds have the same hardness as natural diamonds, so they reach the highest on the Moh scale possible, a 10.

Image by the National Park Service. Public Domain.

Cubic zirconia hits an  8.5 on the scale. This means that lab diamonds have the highest resistance to scratching. It's fairly easy to scratch cz stones, which damages their appearance and can make them appear dull and foggy. This is why cz is not recommended as an alternative diamond engagement ring. 


Because cubic zirconia is manmade, they are able to produce a rainbow of colored gems from them. Not only can they be any color, you won't have to be worried about color zoning, or light pigmentation. 

Lab created diamonds come in other colors too, but only the same colors natural diamonds can be mined in also. They also typically have more pigmentation than natural fancy colored diamonds. Fancy colored lab diamonds are cheaper than fancy colored natural diamonds, but nowhere near as cheap as colored cubic zirconia.

Bottom Line: Cubic Zirconia vs Lab Diamond

As you can see, there are different reasons other than pricing alone why someone might want a cubic zirconia engagement ring over a lab grown diamond. There are also reasons why someone might want the lab diamond over a CZ. 

Because in short, yes, you're going to save thousands on when buying cubic zirconia as opposed to lab diamonds. And yes, cubic zirconia gemstones are eye-clean and don't have any natural inclusions. Their price does not alter based on appearance. The have a fantastic flashy sparkle, even if it looks a little overkill. Some people love the dramatics, or it really doesn't make a difference to them. 

But they have some downsides that lab diamonds don't. With any kind of diamond, lab or natural, you can pass that down from generation to generation. The stones have the durability to last that long. Cubic zirconia scratches over a much shorter amount of time, leaving the surface foggy and unappealing. This usually happens within just a couple years.

Neither of the gemstones hold a lot of value, since CZ is readily available and easy to make and lab diamond prices fluctuate so much. It's best not to invest in either of these stones for future monetary value.

While only you know which gemstone is best for your situation and budget, we recommend that you choose a lab grown diamond over a cubic zirconia as a center stone for your engagement ring. 

We recommend them for many reasons. First, it can be very difficult to find high quality cubic zirconia rings, because not many seek them out. You can find some on Zales and Kay's website set in 10K gold. But many warranties won't cover routine maintenance on these rings. In fact, it can be difficult to find a jeweler to work on at all. 

Honestly, keeping up with routine maintenance for a stone like cubic zirconia would cost you more repairing the gold than the stone itself. But with a lab created diamond, you can choose from high quality metals and even platinum, which might even save you having to need routine maintenance. Furthermore, there are places like James Allen that will give you a lifetime warranty with your lab diamond for free. 

The main reason you should buy a lab diamond instead of a cz for an engagement ring is because cubic zirconia doesn't last. Most people hold sentiment with their jewelry, so they don't want to have to be having to replace it. And because the demand is not high for cubic zirconia rings, there's a good chance a specific design won't be in stock anymore. 

If you want a beautiful and lasting center stone for an engagement ring and are willing to spend a little cash to do so, a lab diamond will be a much better investment. But, if a CZ ring is more in your budget, there's nothing wrong with that either. The choice is up to you! 

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