If you're shopping for a sparkly stone and see options labeled “lab-grown” or “cubic zirconia,” it can be hard to tell the difference—especially at first glance.
But while both are man-made, they vary dramatically in quality, durability, and value. Whether you're choosing an engagement ring or just want your jewelry to last, understanding how these stones compare is key.
What Are Lab Diamonds?
Lab-grown diamonds are real diamonds created in a lab using high-tech methods that mimic the earth’s natural diamond-forming process. They are made of pure carbon atoms arranged in the same crystalline structure as mined diamonds, resulting in the same hardness, brilliance, and optical properties.
Unlike diamond simulants, lab-grown diamonds are chemically and physically identical to natural diamonds. They are graded by the same 4Cs—cut, color, clarity, and carat—by reputable gemological labs like IGI or GIA. The only real difference is origin: lab diamonds are formed in weeks, not billions of years, and they often cost 30–50% less than their mined counterparts.
What is Cubic Zirconia?
Cubic zirconia (CZ) is a lab-created gemstone made from zirconium dioxide. Though it may resemble a diamond at first glance, it is not chemically, physically, or optically related to real diamonds. Unlike lab-grown diamonds, which are composed of carbon, CZ is the cubic crystalline form of zirconium oxide—an entirely different material.
CZ is produced by melting zirconium oxide with stabilizing agents like magnesium and calcium at temperatures nearing 4,982ºF (2,750ºC). As the molten material cools, crystals form, which are then cut and polished to resemble diamonds. Each lab may use slightly different processes, but the result is a colorless, internally flawless stone designed to mimic diamond sparkle.
Unlike diamonds, CZ is not graded by the 4Cs, but instead categorized by a separate letter-based quality system. Grade A are lowest grade, easily scratched or chipped. AAA are mid-grade, often used in fashion jewelry. AAAAA (5A): The highest quality CZ, often hand-cut and polished, offering the best optical resemblance to diamonds
Despite being flawless to the eye and highly affordable, CZ lacks the brilliance, hardness, and long-term durability of real diamonds. It scores 8–8.5 on the Mohs scale (compared to 10 for diamonds), making it more prone to scratching and clouding over time.
It’s also slightly denser than diamond, meaning a CZ stone will be physically smaller than a diamond of the same carat weight. That’s why CZ is best suited for short-term or fashion use, rather than lifelong pieces like engagement rings.
What is the Difference Between Cubic Zirconia vs Lab Diamond?
| Feature | Natural Diamond | Lab Grown Diamond | Cubic Zirconia |
| Material | Pure carbon | Pure carbon | Zirconium dioxide (synthetic) |
| Hardness | 10 on the Mohs scale | 10 on the Mohs scale | 8–8.5 on the Mohs scale |
| Refractive Index | 2.42 | 2.42 | 2.15-2.18 |
| Dispersion | 0.044 | 0.044 | 0.058-0.066 |
| Certificate | GIA/IGI | GIA/IGI | / |
| Cost | Most expensive option due to rarity and mining costs | 50–70% cheaper than natural diamonds | Much cheaper than both natural and lab-grown diamonds |
| Durability | Extremely durable, suitable for daily wear | Extremely durable, suitable for daily wear | Prone to scratches and clouding over time |
| Ethical & Environmental Impact | Higher environmental impact due to mining | Minimal environmental and ethical impact | Environmentally friendly, but less durable |
Though both lab diamonds and cubic zirconia (CZ) are created in laboratories, they are fundamentally different stones—in composition, performance, and long-term value.
Here’s how they compare across key characteristics:
Composition
Lab-grown diamonds are composed of pure carbon atoms, arranged in the same crystal lattice as natural diamonds. Cubic zirconia is made from zirconium dioxide, a synthetic material with no chemical similarity to real diamonds.
Appearance and First Impressions
While both stones can look brilliant when new, CZ often gives off a glassy, overly flawless shine that may look artificial in natural light. Lab-grown diamonds, by contrast, are visually identical to natural diamonds, with real depth, fire, and clarity—the kind that makes a ring look and feel like fine jewelry, not costume jewelry.
Sparkle and Refraction
Lab-grown diamonds offer authentic brilliance and fire thanks to their natural light performance. CZ has high initial sparkle but tends to show more rainbow-colored flashes, which can look artificial under certain lighting.
Lab grown diamonds have a refractive index of 2.42, creating sharp, dazzling sparkle as same as natural diamond. CZ’s refractive index is lower at 2.15–2.18, resulting in less crisp and more diffused light reflection.
How They Age Over Time
CZ may sparkle on day one, but with regular wear, it tends to scratch, dull, or cloud, especially when exposed to water, skincare products, or daily friction. Lab-grown diamonds are incredibly hard(10 on the Mohs scale)—just like mined diamonds—so they resist wear and retain their brilliance for decades, making them ideal for engagement rings or heirloom pieces.
Perceived Value and Meaning
Even if your CZ ring looks nice, many consumers report that it “feels fake” once they learn more about it. Lab-grown diamonds, on the other hand, are real diamonds, graded by certified labs and made to last. They carry weight—not just physically, but emotionally, because they hold up to the significance of the moment they represent.
Size and Wearability
Because CZ is denser than diamond, it feels heavier for its size and may sit differently in a setting. For buyers expecting a certain visual scale per carat, this can be surprising. With lab-grown diamonds, what you see is what you get—a true-to-size diamond with natural proportions and ideal light performance.
Long-Term Investment vs. Short-Term Sparkle
CZ is great for fun, affordable, fashion-forward looks—but it’s not made to last. If you’re looking for a stone that holds its beauty (and story) over time, a lab-grown diamond is a far better investment, both financially and emotionally.
Why Choose Lab-Grown Diamonds Over Cubic Zirconia?
While cubic zirconia may offer a quick sparkle at a lower cost, lab-grown diamonds stand out as the better long-term choice—especially for meaningful jewelry like engagement rings or anniversary pieces.
1. Real Beauty That Lasts
Lab-grown diamonds are chemically, physically, and optically identical to mined diamonds. They’re a true investment in durability and brilliance, scoring a 10 on the Mohs scale—meaning they resist chips, scratches, and clouding over time. CZ, by comparison, may dull or degrade with regular wear.
2. Better Quality, Within Reach
Because lab-grown diamonds are created under controlled conditions, you can often find stones with exceptional clarity and cut—without paying the premium price of natural diamonds. That means more sparkle, better color, and fewer inclusions for your budget.
3. Ethical & Transparent Origin
With lab-grown diamonds, there’s no mystery behind the source. Unlike natural diamonds that may raise ethical concerns, lab-grown stones are conflict-free and fully traceable, giving you peace of mind with your purchase.
4. Lower Environmental Impact
Choosing a lab diamond helps reduce the environmental footprint associated with traditional mining. There’s no large-scale excavation, water pollution, or community displacement, making it a more sustainable choice for conscious consumers.
5. Versatility in Style and Selection
Lab-grown diamonds are available in every popular cut and size, from oval and pear to emerald and princess. Whether you’re creating a custom engagement ring or building a fine jewelry stack, the options are virtually endless—and certified.
In short, lab-grown diamonds offer lasting value—both visually and ethically—whereas CZ is best reserved for short-term or costume use. If your jewelry is meant to symbolize something real, your stone should be real too.
Conclusion
Cubic zirconia may offer a diamond-like look at a lower cost, but it falls short in brilliance, durability, and longevity. If you're investing in a piece of jewelry that represents love, commitment, or personal value, lab-grown diamonds provide unmatched sparkle, strength, and significance—at a more accessible price than natural diamonds and with a much longer lifespan than CZ.
Elora only uses certified lab-grown diamonds, selected for their beauty, quality, and enduring brilliance. Explore our collection to see the difference for yourself.