Lab-Grown Diamonds vs. Cubic Zirconia: The Complete Buying Guide (2023)

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Are you looking for jewelry and have considered diamond jewelry but think it’s too expensive? Then you may have come across either cubic zirconia or lab-grown diamonds. But one is a real diamond, and the other is not. Learn what is real and the right choice for you in our complete buying guide to lab-grown diamonds vs. cubic zirconia.

In this buying guide, we’ll compare lab-grown diamonds vs. cubic zirconia and their respective advantages and disadvantages. We’ll compare prices, quality, brilliance, and beauty. And we’ll explore their distinct characteristics, including their crystal structure, carat weight, and position on the Mohs hardness scale, to help you better understand the differences between cubic zirconia and lab-created diamonds.

We will also highlight the benefits of choosing lab-grown diamonds over natural or mined ones while discussing some potential drawbacks of cubic zirconia stones. Finally, we’ll provide an in-depth cost comparison between lab-grown diamonds and cubic zirconia for those seeking an affordable gemstone who may mistakingly believe that real diamonds are expensive.

This information will equip you with all you need to make an informed decision in your search for high-quality fine jewelry featuring either lab-created diamonds or synthetic diamond simulants like cubic zirconia. If you’re wondering about moissanite, then read our guide to lab-grown diamonds vs. moissanite.

The 3 best places to buy lab-grown diamonds

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What is a Lab-Grown Diamond?

A lab-grown diamond, also known as a lab-created or simply lab diamond, is a real diamond and gaining popularity in the jewelry industry for ethical sourcing and affordable pricing.

Lab-grown diamonds are created using advanced technology that replicates the natural process of diamond formation. These high-tech processes include High Pressure-High Temperature (HPHT) and Chemical Vapor Deposition (CVD). They grow from a tiny “seed” into a rough diamond over months.

The result? A beautiful, sparkling gemstone with the exact same properties as mined diamonds. They’re just as hard, refractive, and brilliant. But here’s the kicker: lab-grown diamonds are eco-friendly. No harmful mining is involved, just clean laboratory environments.

Lab-grown diamond polish and symmetry: Example diamond
A lab-grown diamond from Ritani

Difference between mined diamonds and lab-grown diamonds

Lab-grown diamonds are made in controlled laboratory conditions within weeks or months, while natural diamonds take billions of years to form deep within the Earth. They have the same properties but different origins.

Ethical considerations

Lab-grown diamonds are environmentally friendly and free from concerns like conflict funding or child labor. No guilt, just sparkle.

Lower prices

We have analyzed the prices of natural and lab-grown diamonds and have found that lab-grown diamonds are 60-80% cheaper than mined diamonds with the exact same properties. See, for example, how much a 1-carat lab-grown diamond costs.

Jewelry applications

Lab-grown diamonds can be used in any jewelry piece. They’re affordable and offer the same quality as mined diamonds, so you can be sustainable without sacrificing style or value.

What is Cubic Zirconia?

Having learned that lab-grown diamonds are indeed real diamonds, what about cubic zirconia?

Cubic zirconia, also known as CZ, is a synthetic diamond simulant composed primarily of zirconium dioxide. This synthetically created stone mimics the look of real diamonds but lacks their hardness and durability.

Cubic zirconia, often used as an affordable diamond alternative, is a synthetic gemstone. Note the keywords diamond alternative and synthetic. That means that, unlike lab diamonds, cubic zirconia is not a real diamond.

This lab-created gemstone has a cubic crystalline form that closely resembles the sparkle and brilliance of real diamonds. It’s worth noting that while both lab-grown diamonds and cubic zirconia stones are lab-created, they differ significantly in their composition and properties. We’ll get to that later.

Lab-grown diamonds vs. cubic zirconia: Cubic zirconia is the cheapest option.

The history of cubic zirconia

Cubic zirconia has been used since the 1970s as an affordable diamond alternative. This synthetically created stone is made from zirconium dioxide and shares a cubic crystalline form with diamonds.

Cubic zirconia chemical structure

In terms of crystal structure, although both share a similar shape (cubic), lab-created diamonds have an identical atomic structure to mined ones due to being pure carbon like them. This is not true for cubic zirconia stones, which lack such uniformity because their primary component is not carbon but oxygen combined with the metallic element zinc.

How cubic zirconia is made

Creating cubic zirconia involves heating powdered ingredients to extremely high temperatures until they melt into a liquid state. The molten material then begins to cool and harden, forming crystals in the process. These crystals are later cut and polished into gemstones that closely resemble real diamonds that mimic different types of diamond shapes and cuts.

The appeal of cubic zirconia over real diamonds

Cubic zirconia offers an affordable diamond alternative for those on a budget because they are much, much less expensive than both mined and lab-grown diamonds. A well-cut cubic zirconia ring can shine brilliantly like a high-quality lab-grown diamond, making them popular in cheaper jewelry.

Cubic zirconia has gained popularity due to its affordability compared to other alternatives, such as synthetic diamond simulants, including moissanite, or options like fine jewelry made with lab-created diamonds.

Another advantage is that it is available in larger carat weights without hefty price tags. This is in contrast to diamonds, including lab-grown diamonds, where prices increase exponentially with carat weight.

Lab-Grown Diamonds vs. Cubic Zirconia: Pros and Cons

When shopping for diamond jewelry, it’s important to understand the differences between cubic zirconia and lab-grown diamonds. These two types of stones offer different benefits and drawbacks that can significantly impact your purchasing decision.

Choosing between lab-grown diamonds and cubic zirconia might seem complicated, but it’s not. Let’s break it down.

Differences between cubic zirconia vs. lab-Grown diamonds

While at first glance, cubic zirconia and lab-grown diamonds may look similar. But there are key differences that you should be aware of.


In terms of composition, too, they vary greatly. While lab-grown diamonds consist almost entirely of pure carbon, just like their natural counterparts, cubic zirconia contains no carbon. Instead, cubic zirconia consists mainly of a stabilized version of the mineral baddeleyite, also known as ‘ZrO2’ or ‘zirconium dioxide’.

Durability and Hardness

On the Mohs hardness scale, for example, while a real diamond ranks at 10 – making it one of the hardest substances known to man – cubic zirconia scores an 8 to 8.5, meaning it’s less durable than its diamond counterparts.

A significant disadvantage of cubic zirconia and its lower hardness grade is that it tends to lose its sparkle and become cloudy over time due to everyday wear and tear. In contrast, lab-grown diamonds will withstand almost anything (bar the rare chipping that a few shapes can be prone to).

The main reason is the difference in hardness, which is often measured on the Mohs scale. While cubic zirconia only manages 8 to 8.5, diamond (mined or lab-created) gains the highest rating.

Mohs hardness scale
HardnessMineral ReferenceAbsolute hardness
6Orthoclase feldspar72
8Topaz (and cubic zirconia)200
9Corundum (and moissanite)400
10Diamond (lab-grown and mined)1500

Clarity Grade

Cubic zirconia often looks “too perfect” because it’s synthetically produced without imperfections. Lab-grown diamonds, on the other hand, have minor inclusions, just as mined diamonds do, giving them an authentic appearance. Learn about lab-grown diamond clarity.

Color Grade

Most cubic zirconia stones appear colorless, while lab-grown diamonds come in various shades. Lab-grown diamonds offer more options, from colorless to near-colorless, and even fancy lab diamond colors like blue and pink.

In a nutshell, cubic zirconia may seem attractive due to its lower price, but it lacks the depth, brilliance, and quality of lab-grown diamonds. So, if you’re a discerning shopper, make an informed decision that suits your needs, preferences, and budget.

Learn more about lab-grown diamond colors.


In terms of environmental impact, both lab-grown diamond and cubic zirconia wins over mined diamonds and other mined gemstones. The process used for creating these high-quality lab stones doesn’t disrupt ecosystems, nor does it involve any human rights issues sometimes associated with traditional mining practices. This makes them more ethical and sustainable choices compared to even some of the supposedly ethically sourced mined counterparts.

Can you tell cubic zirconia from lab-grown diamonds?

The world of lab-grown diamonds and cubic zirconia stones can be confusing for many and, at first, glance, may look similar. Both are popular choices in the jewelry market, but can you tell the difference between lab-grown diamonds vs. cubic zirconia?

Unlike lab-grown diamonds vs. mined diamonds, which you cannot tell apart (because they are the same), spotting cubic zirconia is easier.

But it may not be how you expect.

  1. Weight: Cubic zirconia is heavier than diamond, and 1-carat of cubic zirconia will be smaller than 1-carat lab-grown diamonds.
  2. Brilliance: Lab-grown diamonds primarily emit white or colorless light, while cubic zirconia disperses a more colorful light, almost like a rainbow of colors.
  3. Clarity: Cubic zirconia rarely has any blemishes or inclusions and is almost too perfect compared to even lab-grown diamonds, which will never be perfect.
  4. Color: Cubic zirconia is typically colorless, while lab-grown diamonds are rarely completely colorless.
  5. Scratches and cloudiness: If the gemstone is scratched or has a cloudy appearance, chances are it’s not a lab-grown diamond but cubic zirconia (or another diamond alternative).

The most obvious and quick way you can tell that a diamond is not a real diamond (mined or lab-created) is by the simulant being too good! The clarity will often be perfect and the color non-existent, i.e., perfectly colorless. They can also appear more glass-like with a sharp and colorful brilliance that nevertheless lacks the depth of real diamonds.

The lack of flaws makes them appear almost fake. Which, if they are trying to imitate diamonds, they are. But they are still real gemstones.

Lab-grown diamonds vs. Cubic Zirconia for Engagement Rings

When selecting the perfect stone for an engagement ring, two options that often come up are lab-grown diamonds and cubic zirconia. Both offer affordable alternatives to pricey mined diamonds but differ significantly in quality, durability, and value.

Cubic Zirconia: The Affordable Diamond Simulant

Cubic zirconia stones, made from zirconium dioxide, have a cubic crystalline form, giving them their name. They rank at 8-8.5 on the Mohs hardness scale, and while this makes them hard enough for everyday wear, they’re not as durable as real diamonds or lab-created diamonds, which score a solid 10 on the same scale (see above).

That makes them less suitable for engagement rings, which should last forever while subjected to everyday wear and tear. Unlike earrings or necklaces, engagement rings are often exposed to brushes and scrubs and should be durable.

The brilliant shine of cubic zirconia may initially resemble that of a diamond’s sparkle, but over time, these synthetic stones may become cloudy and lose their luster, unlike lab-grown or mined diamonds whose brilliance lasts forever.

Lab-Grown Diamonds: Affordable but identical to mined diamonds

Mined natural diamonds, formed deep within Earth’s mantle over billions of years under high-pressure conditions, are identical in crystal structure to lab-grown diamonds. These created stones consist of pure carbon, just like natural ones, making them ‘real’ too!

A major advantage is that these lab-grown beauties cost significantly less than mined diamonds without compromising on carat weight or highest quality characteristics such as cut, color, and clarity – ideal attributes when considering an important jewelry purchase like engagement rings! Additionally, being environmentally friendly with no mining involved adds another feather to its cap!

That’s why we recommend lab-grown diamonds for engagement rings. Learn how to save and find the perfect lab-grown diamond engagement ring and how much a lab-grown diamond engagement ring costs.

Cost Comparison: Lab-Grown Diamonds vs. Cubic Zirconia

If you want bling on a budget, let’s compare the costs of lab-grown diamonds vs. cubic zirconia. It’s like a battle of sparkle versus savings.

Lab-Grown Diamond Costs

Lab-grown diamonds are 60-80% cheaper than mined diamonds. No need to worry. They’re not imitations. These lab-created diamonds have the same sparkle and durability as mined diamonds. Plus, they’re eco-friendly because no mining is involved. Shine bright and save money.

Here’s an overview of the average prices of round brilliant lab-grown diamonds (the most popular lab-grown diamond shape).

Lab diamond carat sizePrice at recommended jeweler
1-carat round lab diamond price$602-1274 at Ritani
2-carat round lab diamond price$1046-3104 at Ritani
3-carat round lab diamond price$2187-6086 at With Clarity
4-carat round lab diamond price$3483-5267 at Ritani
5-carat round lab diamond price$4831-7436 at Clean Origin
6-carat round lab diamond price$7460-14372 at Clean Origin
Lab-grown diamond prices collected by (2023)

Cubic Zirconia Costs

Cubic zirconia is the budget-friendly option. Though cubic zirconia costs less than even lab-grown diamonds, its durability is not as long-lasting and may require more frequent replacements due to chipping or scratching. These sparklers can easily chip or scratch over time.

But cubic zirconia is incredibly affordable. You can find a 1-carat cubic zirconia for about $20, while a 1-carat lab-grown diamond costs from $600-1300 (mined diamonds are a lot more expensive).

You can even pick up a pair of cubic zirconia earrings set with 1 carat CZ each for less than $40.

There really is no beating the price of cubic zirconia. But, as you will have learned, they do not look like diamonds, and their durability is not even comparable to the longevity of forever diamonds.

Quality vs. Price

As mentioned, when it comes to price, cubic zirconia is unbeatable. But, considering value, lab-grown diamonds win the crown. They offer long-term durability, beauty, and potential resale value. Cubic zirconia may save you money upfront but can’t compete in the long run. Pay a little more, and get a lot more.

Why Choose Lab-Grown Diamonds Over Cubic Zirconia?

When selecting a precious stone for your fine jewelry, the choice often boils down to lab-grown diamonds and cubic zirconia. Both offer an affordable diamond alternative but differ in several crucial aspects.

Disadvantages of Cubic Zirconia

While cubic zirconia is often touted as a budget-friendly alternative to diamonds, it’s important to understand that the two have significant differences. Let’s delve into some of the key disadvantages associated with cubic zirconia.

Aesthetic appeal

While both types of gems can be cut into various shapes with similar carat weight options available, there’s no denying that the two have significant differences. Diamonds far surpass those of cubic crystalline form found in CZ stones.

Durability and Hardness

Cubic zirconia ranks much lower on the Mohs hardness scale, making them less durable than lab-grown diamonds, which rank 10 (the highest). This means that cubic zirconia can easily get scratched, chipped, or even cloudy over time compared to the resilient option of lab-grown or mined diamonds.

Artificial Brilliance and Fire

Although they may look similar at first glance, cubic zirconium dioxide does not possess the same brilliance (the white light reflected from within a gem) as real diamonds do. Moreover, its fire (the dispersion of light into colors) is excessively colorful and high—higher than any real diamond—which makes it look somewhat artificial when closely inspected. The brilliance lacks the depth and playfulness that you experience with real diamonds.

Poor Heat Conductivity

Cubic zirconia doesn’t handle heat well. Unlike lab-grown diamonds, cubic zirconia is a poor conductor of heat. This is one way to test whether the stone is made of diamond or a diamond simulant.

Lab-grown diamonds vs. cubic zirconia FAQs

Are lab-grown diamonds better than cubic zirconia?

Yes, lab-grown diamonds are superior in quality and durability compared to cubic zirconia.

How to tell the difference between cubic zirconia and a lab-created diamond?

The main differences lie in their hardness, refractive index, and specific gravity, which can be identified by a professional gemologist using specialized equipment. For the layperson, cubic zirconia may sparkle with a more glass-like appearance without the depth of a diamond’s brilliance.

Can jewelers tell the difference between lab-grown diamonds vs. cubic zirconia?

Yes, most jewelers should be able to spot the difference between lab-grown diamonds and cubic zirconia pretty easily and with the naked eye. However, they can also easily distinguish between lab-grown diamonds and cubic zirconia using common and cheap instruments.

Do lab-grown diamonds pass a diamond tester?

Absolutely. Lab-grown diamonds will pass traditional thermal conductivity testers because they have similar physical properties as mined diamonds.

Does cubic zirconia pass a diamond tester?

No, cubic zirconia will not pass a diamond tester, and it’s pretty easy, even with the naked eye, to distinguish cubic zirconia from lab-grown or mined diamonds.

Summary of lab-grown diamonds vs. cubic zirconia

Lab-grown diamonds and cubic zirconia are both popular choices for shoppers looking for affordable alternatives to natural diamonds, but there’s a catch.

Lab-grown diamonds are a sustainable and ethical choice compared to mined diamonds, with the same chemical composition and physical properties. At the same time, cubic zirconia is just a synthetic material trying to imitate the real deal.

Regarding cost, lab-grown diamonds may be a bit pricier than cubic zirconia, but they offer better value in terms of quality and longevity.

Remember that despite similarities in appearance between lab-grown diamonds vs. cubic zirconia, notable differences remain, such as long-term resilience, which should be considered before deciding what type suits your needs best!

So, if you want a sparkly substitute that won’t break the bank and will last, lab-grown diamonds are the way to go. Lab-grown stones provide ethical advantages over traditional mining practices while offering comparable beauty and quality at lower prices than mined ones.

If you’re looking for fine jewelry without breaking your bank account, go for the real deal with lab-grown diamonds.

Where to Buy Lab-Grown Diamonds

At, we review lab diamond jewelers, and based on our numerous in-depth reviews, we recommend the following places to buy lab-grown diamonds (over cubic zirconia).

Ritani review ⭐⭐⭐⭐⭐


Ritani tops our list of the best and cheapest places to buy lab-grown diamonds because of their market-leading low prices and price transparency, the most extensive inventory of lab diamonds, customization options, and jewelry store partnership.

Ritani tops our list of the best and cheapest places to buy lab-grown diamonds vs. cubic zirconia.
Clean Origin is another of our favorite places to buy lab-grown diamonds vs. cubic zirconia.
Clean Origin review ⭐⭐⭐⭐⭐

Clean Origin

Clean Origin is another of our favorite places to buy lab-grown diamonds. We recommend Clean Origin for its unbeatable prices, a large selection of lab-grown diamonds and jewelry, and excellent support (plus 100-day risk-free returns).

Grown Brilliance review ⭐⭐⭐⭐⭐

Grown Brilliance

Grown Brilliance is our favorite for lab-grown diamond engagement rings and unique jewelry design collections. In addition, Grown Brilliance’s prices are excellent, and so is the shopping experience.

Grown Brilliance is our favorite for lab-grown diamond engagement rings as well as pendants.
James Allen is one of our best-rated places to buy lab-grown diamonds vs. cubic zirconia.
James Allen review ⭐⭐⭐⭐⭐

James Allen

James Allen is among our best-rated places to buy lab-grown diamonds. The service is top-notch, prices are low, the selection is enormous, and the quality and craftsmanship are superb.

Brilliant Earth is the leading sustainable lab-grown diamond jeweler and one of the best places to buy lab-grown diamonds vs. cubic zirconia.
Brilliant Earth review ⭐⭐⭐⭐⭐

Brilliant Earth

Brilliant Earth is the leading sustainable lab-grown diamond jeweler. Their deep commitment to sustainability, including being the only seller of sustainable graded lab diamonds, sets them apart. The prices are excellent, too, and they have an extensive inventory of beautiful lab diamonds.

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Rolf Hartmann
Rolf Hartmann

Rolf Hartmann has decades of experience in the jewelry industry. He knows everything you need to know to find the perfect diamond. He's an expert in lab-grown diamonds and has followed the exciting development of lab diamonds from industrial usage to the incredible gemstone quality that lab-grown diamonds are today. Rolf guides you to find the right diamond at the best possible price and expertly and transparently reviews all lab-grown diamond sellers.

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