What Is Cubic Zirconia? How It Compares With Diamonds and Other Gemstones

on Nov 03 2026
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    A gemstone can look just like a diamond, sparkle beautifully, and catch your eye, but it may be made from a completely different material. Cubic zirconia (CZ) is one such example. Cubic zirconia is a man-made gemstone made in a laboratory. It is designed to look like a diamond and is often used in jewelry as a cheaper alternative.

    Although it looks similar to a diamond, it is not the same. It has a different chemical makeup, shines differently and is less durable. This is important when comparing cubic zirconia with natural diamonds, lab-grown diamonds and moissanite. They may all look similar, but they are made from different materials and have different qualities.

    Knowing what cubic zirconia is can help you understand how it looks, how long it lasts, how to care for it, and whether it is the right choice for your jewelry.

    What Is Cubic Zirconia?

    Cubic zirconia (CZ) is a man-made gemstone made from zirconium dioxide (ZrO₂). It is created in laboratories and used in jewelry as a cheaper alternative to diamonds. It is called a diamond simulant, which means it is made to look like a diamond but is made from a different material.

    Unlike natural diamonds, cubic zirconia is not mined from the earth. It is made in a lab and can be cut and polished to give it a beautiful shine. However, CZ is not just ordinary glass. It is a separate gemstone material that can sparkle and look very similar to a real diamond.

    Is Cubic Zirconia a Real Gemstone or a Fake Diamond?

    It depends on what you mean by "real." Cubic zirconia (CZ) is a real, man-made gemstone, but it is not a real diamond. It is made to look like a diamond without being made from the same material. Here is the difference:

    • Natural diamond: A real diamond formed naturally inside the Earth.

    • Lab-grown diamond: A real diamond made in a laboratory. It has the same basic properties as a natural diamond.

    • Cubic zirconia (CZ): A man-made gemstone designed to look like a diamond, but made from a different material.

    So, cubic zirconia is a real gemstone, but it is not a diamond. The correct term for it is a diamond alternative or diamond simulant.

    What Is Cubic Zirconia Made Of and How Is It Manufactured?

    Cubic zirconia is made from a material called zirconium dioxide, which contains zirconium and oxygen. Unlike natural diamonds, which form deep inside the Earth over millions of years, cubic zirconia is made in a laboratory.

    The process involves heating zirconium oxide powder until it melts. As it cools, it forms crystals that can later be cut and polished into gemstones. This process allows manufacturers to make cubic zirconia in different colours. Clear CZ is made to look like a diamond, while coloured versions can look like other gemstones. Because it is made in a lab, cubic zirconia is also easier and cheaper to produce than natural diamonds.

    Why Is Cubic Zirconia Available in Different Colors?

    Cubic zirconia is available in many colors, not just clear or colorless. It can be made in pink, yellow, blue, green, purple, and black. This makes it a popular choice for jewelry because it offers lots of color options at an affordable price.

    For example, a pink cubic zirconia can look similar to a pink diamond but costs much less. The colour is added during the manufacturing process, so it does not mean the stone is a natural gemstone.

    Cubic Zirconia vs Diamond, Lab-Grown Diamond and Moissanite

    four diamond like gemstone, placed in a line. CZ, diamond, lab-grown diamonds and moissanite

    Property

    Cubic zirconia

    Natural diamond

    Lab-grown diamond

    Moissanite

    Composition

    Zirconium dioxide

    Carbon

    Carbon

    Silicon carbide

    Origin

    Laboratory-created

    Naturally formed

    Laboratory-created

    Usually laboratory-created in jewelry

    Is it a diamond?

    No

    Yes

    Yes

    No

    Mohs hardness

    8.5

    10

    10

    Approximately 9.25

    Appearance

    Diamond-like sparkle

    Characteristic diamond brilliance and fire

    Essentially the same material appearance as natural diamond

    Strong brilliance and noticeable rainbow fire

    Cubic Zirconia vs Natural Diamond

    The biggest difference between cubic zirconia and a natural diamond is the material they are made from. Diamonds are made of carbon, while cubic zirconia is made from zirconium dioxide. This difference affects how hard they are, how they shine, and how long they last.

    A diamond has a hardness rating of 10 on the Mohs scale, while cubic zirconia has a rating of around 8.5. This means diamonds are much harder to scratch and generally last longer. They also shine differently. Cubic zirconia can show more rainbow colors when light hits it, while diamonds have a different kind of sparkle.

    Both can look beautiful in jewelry. Cubic zirconia is a good choice if you want a diamond-like look at a lower price.

    Cubic Zirconia vs Lab-Grown Diamond

    Cubic zirconia and lab-grown diamonds are sometimes confused because both are made in laboratories. However, they are two very different materials. A lab-grown diamond is a real diamond made in a laboratory. It has the same basic composition and properties as a natural diamond. Both can be cut and polished to look beautiful in jewelry, but they are not the same.

    If you want jewelry that looks like a diamond but costs less, cubic zirconia is a good option. However, if you want a real diamond without paying the price of a natural one, a lab-grown diamond may be a better choice. 

    Cubic Zirconia vs Moissanite

    Moissanite is another popular alternative to diamonds, but it is different from cubic zirconia in terms of material, shine, and durability. Moissanite is made from silicon carbide.

    One major difference is their hardness. Moissanite has a hardness rating of 9.25 on the Mohs scale, while cubic zirconia has a rating of 8.5. This means moissanite is harder to scratch and more durable.

    They also shine differently. Moissanite produces more colorful rainbow flashes when light hits it, while cubic zirconia has a different kind of sparkle. Cubic zirconia is generally cheaper, while moissanite is more durable and resistant to scratches. 

    Cubic Zirconia vs Natural Zircon

    Despite their similar names, cubic zirconia and zircon are two different materials. Natural zircon is a naturally occurring gemstone with the chemical formula ZrSiO₄. Cubic zirconia is a manufactured material with the chemical formula ZrO₂. Zircon occurs naturally in several colors, including blue, red, yellow, green, and brown. Colorless zircon has also been used as a diamond alternative because of its brilliance and fire.

    How Does Cubic Zirconia Look Compared With a Diamond?

    Cubic zirconia is popular because it can reproduce many of the visual qualities associated with diamonds. A well-cut colorless CZ stone can appear bright, clear,r and highly reflective. From a normal viewing distance, an inexperienced observer may not immediately recognise the difference between CZ and diamond. 

    The differences become easier to understand when you look at how each material handles light. Three terms are especially useful:

    • Brilliance refers to the white light returned through the crown of a gemstone.

    • Fire describes the colored flashes produced when white light separates into spectral colors.

    • Scintillation refers to the flashes of light and dark that appear when the stone or observer moves.

    Cubic zirconia can display slightly greater fire but less brilliance than diamond. Its flashes can appear broader and more colorful. This is why a CZ stone can sometimes look more rainbow-like than a diamond, especially under direct lighting.

    How Durable Is Cubic Zirconia in Everyday Jewelry?

    Cubic zirconia has a Mohs hardness of approximately 8.5, which makes it a relatively hard material suitable for jewelry. However, hardness is only one part of durability. The Mohs scale measures a material's resistance to scratching. It does not tell you everything about how a gemstone will respond to hard impact, repeated abrasion, or everyday wear.

    A diamond is harder than cubic zirconia, which means its polished surface is more resistant to scratching. CZ can gradually develop visible wear, particularly around exposed facet edges. 

    Does Cubic Zirconia Turn Yellow?

    Yes, colorless cubic zirconia can develop a yellowish appearance over time. Yellowing is a potential characteristic of CZ. It should not be described as having the same long-term color stability as diamond.

    How Long Does Cubic Zirconia Last?

    There is no reliable lifespan for cubic zirconia jewelry. A stone worn occasionally in a protected setting will experience different conditions from one worn every day in an exposed ring. Its long-term appearance depends on factors such as:

    • Frequency of wear.

    • Exposure to abrasive surfaces.

    • Impact and accidental damage.

    • Cleaning and maintenance.

    • Setting design.

    • Changes in the material over time.

    For occasional jewelry, it can offer an appealing combination of appearance and affordability. For a ring intended to withstand years of frequent wear, the difference in scratch resistance between CZ and diamond or moissanite deserves careful consideration.

    How Can You Identify Cubic Zirconia?

    Identifying cubic zirconia is not always as simple as looking at a stone. A clear, well-cut CZ can resemble diamond, particularly in a finished jewelry setting. Professional gemologists use a combination of physical and optical characteristics, along with appropriate instruments, to distinguish different gemstone materials.

    Does Cubic Zirconia Pass a Diamond Tester?

    Conventional thermal diamond testers are designed to distinguish diamond from materials with different thermal conductivity, including cubic zirconia. Cubic zirconia will generally not register as diamond on a correctly functioning thermal tester under appropriate testing conditions.

    Moissanite creates a complication. Some thermal-only diamond testers can mistake moissanite for diamond because of its thermal properties. This is why modern testing equipment may combine thermal and electrical conductivity measurements to distinguish between different materials.

    Can You Identify CZ by Looking at It?

    There are visual characteristics of CZ that can provide clues, but none should be treated as definitive proof on their own.

    For example:

    • CZ can show broad, noticeable rainbow flashes.

    • Its facets may develop wear more readily than diamond.

    • Larger CZ stones can have a visual appearance that differs from diamond.

    • A stone's overall appearance changes with its cut, lighting, and cleanliness.

    For authenticity of the stone, ask for appropriate documentation and have the stone examined by a qualified gemologist or independent gemological laboratory.

    For buyers in the United States, the Federal Trade Commission's Jewelry Guides also guide how sellers should describe simulated and laboratory-created diamonds. Simulated stones should be clearly identified as imitations rather than represented as diamonds.

    Read: How To Tell If Diamond Is Real

    What Determines Cubic Zirconia Quality and Price?

    Not all cubic zirconia stones look identical. Two stones with the same shape and size can have different appearances because of differences in cutting, polishing, and manufacturing quality. When evaluating a CZ stone, focus on the characteristics that you can actually assess rather than relying entirely on a seller's grade description.

    What Is the Best Grade of Cubic Zirconia?

    You may encounter commercial terms such as 5A, AAAA, premium CZ, and high-quality cubic zirconia when shopping online. These labels are not a universally consistent gemological grading standard. Different sellers may use their own descriptions and criteria.

    A higher grade label does not prove that a stone has superior cut quality, better color, or greater durability. Instead of relying only on the grade, ask the seller:

    1. What criteria are used to assign the grade?

    2. Are the stone dimensions provided?

    3. Are clear photographs available?

    4. Is the stone described as colorless or near-colorless?

    5. What is the return or replacement policy?

    A seller who can explain the actual characteristics of a stone gives you more useful information than one who simply advertises it as the highest grade.

    How Much Does Cubic Zirconia Cost?

    Cubic zirconia is much less expensive than natural diamonds and is also an affordable alternative to many other diamond-like gemstones. The price of a finished CZ jewelry piece can still vary depending on:

    • Stone size and cutting quality.

    • Jewelry design.

    • Type of metal used.

    • Complexity of the setting.

    • Brand and craftsmanship.

    • Retailer pricing.

    Does Cubic Zirconia Have Resale Value?

    Cubic zirconia generally has very limited standalone resale value. Unlike natural diamonds, it does not have the same established resale market based on rarity and recognised grading characteristics.

    The metal, craftsmanship, or brand associated with a finished piece contribute to its value, but that should not be confused with the resale value of the CZ stone itself.

    What Cleaning Methods Should You Avoid for CZ?

    Avoid harsh chemicals, abrasive cleaners, and rough scrubbing that could damage the jewelry's finish. GIA lists ultrasonic and steam cleaning as safe for CZ itself. However, that does not mean every finished jewelry piece is suitable for these methods.

    A ring or necklace may contain other gemstones, treatments, or construction elements that require different care. When you're unsure, warm soapy water is the safer starting point. Follow the jewelry manufacturer's instructions or ask a jeweller before using professional cleaning equipment.

    Is Cubic Zirconia the Right Choice for You?

    Cubic zirconia is a great option if you love the look of diamonds but don't want to spend as much money. It is affordable, comes in different colors, and can look very similar to a diamond.

    However, it does have some downsides. CZ is softer than diamonds and moissanite, so it can get scratched more easily. Over time, it may also lose some of its shine or turn yellow. It also does not have the same value as natural or lab-grown diamonds.

    If you want beautiful jewelry at an affordable price, cubic zirconia can be a good option. But if you want a real diamond without paying the price of a natural diamond, a lab-grown diamond is worth considering.

    At Diagaa, we focus on genuine natural and lab-grown diamonds rather than alternatives like cubic zirconia and moissanite.

    You can learn explore our lab-grown diamond engagement ring and natural diamond engagement rings.

    Sources:

    Frequently Asked Questions

    Yes. In India, cubic zirconia is commonly known as American diamond (AD). Both names usually refer to the same man-made stone, which is designed to look like a diamond. Despite its name, American diamond is not a real diamond.

    Cubic zirconia can lose some of its sparkle over time due to dirt, oil, scratches, and regular wear. Cleaning it regularly can help restore its shine. However, deep scratches and surface damage cannot be removed through normal cleaning.

    Yes, cubic zirconia jewelry can be worn regularly, but it needs proper care. It is more likely to get scratched than a diamond, especially with everyday use. Removing it during activities like exercising, swimming, and cleaning can help keep it in good condition.

    No, cubic zirconia itself does not tarnish. However, the metal used to make the jewelry can tarnish or change colour over time. For example, sterling silver settings may develop a dull or dark appearance with regular wear.

    Yes. Cubic zirconia has a hardness rating of 8.5 on the Mohs scale, which makes it fairly hard but not scratch-proof. It can develop scratches with regular wear, especially when stored with harder gemstones like diamonds.

    Cubic zirconia generally has very little resale value compared with natural and lab-grown diamonds. It is an affordable jewelry alternative, but it is not usually purchased as an investment. The resale value of the jewelry will also depend on the metal used in its setting.

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    Diagaa Jewelry is dedicated to creating exquisite diamond jewelery while helping customers make confident choices. Our experts share insights on diamonds, engagement rings, wedding jewelery, and gifting trends to inspire every special occasion.

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