Lab-Grown Diamond Versus Cubic Zirconia

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Lab-Grown Diamond Versus Cubic Zirconia

Hint: A lab-grown diamond is still a diamond.

Do you adore the sparkle, luster, and overall look of diamond jewelry, but want to avoid spending the cold, hard cash required to fully bling out? If this sounds like you, cubic zirconia may be something to consider.

This affordable stone was once a staple for Millennial youth (remember those earring carousels at Claire’s?), and has since evolved into beautiful pieces that, to the untrained eye, can be tough to differentiate from real diamonds. "I love that people can feel good regardless of how much they spent [on cubic zirconia jewelry]," says jewelry designer Idunnu Tomori.

Still, as lab-grown diamond creation evolves as well, there can be some confusion as to what constitutes a synthetic, or simulated, diamond, and what qualifies as a real, true stone. And if you’re curious about the differences between lab-grown pieces and cubic zirconia, you’ve come to the right place. Read on to uncover how they vary in the most important ways, including cost, durability, and sparkle.

A lab-grown diamond is just that: a diamond grown in a lab. Its chemical makeup is the same as a natural diamond, as they are both comprised of pure carbon. However, lab-grown stones are an environmentally friendly choice for those searching for an ethically sourced and sustainably grown option.

Today, the most common process for creating a lab-grown diamond is called chemical vapor deposition, which places a small, slim slice of an already existing diamond (which can either be natural or lab-grown) in a vacuum. The vacuum then mimics the intense pressure and heat needed to create a naturally-occurring diamond, which then results in a stone that's almost identical to its natural look-alike.

According to jewelry designer Jean Dousset, lab-grown diamonds have become a popular choice for couples and will only continue to become more popular throughout the next few years. "They will continue to exponentially increase in popularity because the quality of lab diamonds, when purchased from the right designer or brand, has become indistinguishable from their mined counterparts," he shares.

Cubic zirconia (CZ) is the crystalline form of zirconium dioxide. Though a version of CZ can technically appear in a naturally formed stone, it is extremely rare, and all CZs on the market today are manmade. CZs are colorless and look like diamonds to the untrained eye, but they do not have the same chemical makeup as diamonds. (As mentioned above, diamonds are carbon and CZs are zirconium dioxide.)  For that reason, they are sometimes called "synthetic" or "simulated" stones when referenced in overlapping spheres.

Though they may look similar to the naked eye, lab-grown diamonds and cubic zirconia vary in many ways, in relation to their pricing, durability, clarity, quality grade, and color, as highlighted below.

Since lab-grown diamonds are not finite in amount, not subject to the same supply chains, and take less labor and energy to produce than traditional mining, they often cost considerably less—sometimes up to 50 percent less—than naturally occurring diamonds of a similar grade. "They put the consumers in charge and allow buyers to splurge on brands, designs, and diamond sizes and quality that they want," says Dousset. "The beauty of lab diamonds is that they allow people to have their desire met while lessening the emotional and financial burden that purchasing a diamond used to represent."

Cubic zirconia stones are even less costly to produce, primarily because they don’t require recreating pre-volcanic conditions that only exist far beneath the Earth’s crust. As such, they often go for a small fraction of what diamonds of similar size and cut would fetch, and the price disparity only increases as the stones increase in size. Per Tomori, a one- or two-carat CZ ring will almost never run you over $100.

Like natural diamonds, lab-grown stones are comprised of pure carbon. They are the hardest substance on earth—a 10 on the Mohs hardness scale—and, thus, are extremely durable. You can knock one around and wear it through physically demanding activities (though not recommended), and there’s very little chance that the stone will fracture unless there's already a preexisting inclusion near the surface.

While CZs are also hard—typically an 8 to 8.5 on the Mohs scale—they aren't as durable as lab-created pieces. They can typically withstand the typical wear and tear of everyday life just fine, but, per Tomori, "you might see some scratches from knocking your hand around."

If durability is important to you, moissanite, another popular and affordable diamond alternative, is harder than CZ. It clocks in between 9.25 and 9.5 on the Mohs scale. 

As we already know, lab-grown diamonds are grown just as natural diamonds are, albeit over a much shorter period of time. Because of this, the opportunity for inclusions, or tiny imperfections that can cloud a stone’s transparency, can arise. On the other hand, cubic zirconia stones are machine-made, so their clarity is based on how they were created. The most important thing to remember, though, is that they will not possess any natural inclusions since they are not naturally formed stones.

Cubic zirconia is slightly denser than a diamond, which makes it a heavier piece. What's more, cubic zirconia and a lab-grown diamond of the same carat weight will not be the same physical size, with the CZ being slightly smaller than the diamond.

As cubic zirconia is not made up of the same material compound as diamond, and thus, they are not graded on the same scale. CZs are instead rated on an overall quality scale of A (1A) to AAAAA (5A), with AAAAA being the highest quality. These ratings are most frequently referenced during wholesale purchases of CZs and are not likely to be displayed in the typical consumer purchase. Per Tomori, the sweet spot for quality and price is AAA, and that’s the one you’ll most often find on the market from reputable sellers.

As for lab-grown diamonds, their clarity grade can range from Flawless (F1) to Included (I3), and they're judged on the same scale as their natural counterparts given that they're both diamonds.  

Whether they’re mined or lab-grown, completely colorless (grade D) diamonds are extremely rare—and extremely expensive. Most couples instead look for diamonds that are near-colorless, or graded G through J. Even in this range, however, any yellow tint that the diamond may take on would not be noticeable to the naked, untrained eye. 

CZs, on the other hand, are entirely colorless. They won’t feature any hue unless it’s intentional.

In the wedding realm, cubic zirconia is usually featured in the glitzy pieces brides don beyond their engagement rings, such as statement chandelier earrings, royal wedding-inspired bridal tiaras, and more. If made with natural or lab-grown diamonds, these pieces would be infinitely more expensive, and not everyone has infinite budgets to splurge on items they may only wear once. 

Tomori also sees many clients purchase CZ stand-ins of their engagement rings and fine jewelry to wear while traveling, or in instances where it may make a person feel more comfortable to have a ring on. "I had a bride who hadn’t even gotten married yet lose her engagement ring," Tomori says. "It’s hard to go around saying you’re engaged and planning a wedding without one on."

"A one-carat or two-carat stone is going to look more natural," says Tomori. "A bigger stone won’t have a lot of clarity, and it will look obviously 'fake.' If we go up to three carats total, [the ring] will be a diamond with settings on the side."

If you’re giving a passing glance to a smaller-sized, quality CZ, it will be difficult to tell the difference between the simulated diamond and the real one. A closer inspection directly under the light, however, may reveal more of an intense, rainbow-hued sparkle coming off a CZ stone, whereas a diamond will reflect more white light. 

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