With so many different mined diamond alternatives in today’s market, it can be difficult to keep up with each one and fully understand the differences between them. And, with lab-grown diamonds becoming more and more popular, we often hear individuals comparing them to other alternatives that are actually quite different. Moissanite, white sapphire, and even glass are occasionally used to approximate the overall look of a diamond, without the steep cost, but probably the most well-known diamond stand in is actually cubic zirconia.

To the untrained eye, comparing cubic zirconia vs. diamond (lab-grown or mined) can be extremely difficult. However, initial appearances aside, there are a number of essential differences that set these stones apart. And, if you’re shopping for a piece of diamond jewelry but want something other than a mined diamond topping it off, then being able to distinguish between lab-created diamonds vs. cubic zirconia can be extremely helpful — both in terms of preparing a budget and setting expectations.


lab grown diamond ring in box

Cubic zirconia vs. diamond grown in a lab: What’s the difference?

Chemically, physically, and optically, lab-grown diamonds are the exact same as mined diamonds. The difference between the two lies within the origin — one comes from the ground and one is man-made in a lab. As you can see in the chart below, lab-created diamonds are formed with the same chemical composition as mined diamonds — carbon arranged in an isometric crystal formation.

Cubic zirconia, on the other hand, is the cubic crystalline form of zirconium dioxide. Although zirconium alone is used in many products, such as dental implants, the crystalline version produces the diamond stimulant that many of us know as ‘CZ’.

Although they look similar to mined or lab-grown diamonds, there are many glaring differences between diamonds and CZs. To start, CZs are made of completely different chemical composition. When comparing a diamond and a CZ side by side, you’ll notice one major difference: the CZ will give off the appearance of a “rainbow effect”. This will often be a dead giveaway that it is not a mined or lab diamond.

CZs are also much softer than diamonds. With the most durability in a mineral, diamonds place a perfect 10 on the Mohs scale of hardness. CZs come in at an 8.5, which allows them to be easily scratched and become foggy over time.

Although the two are very different gems, it’s likewise important to discuss cubic zirconia vs. diamond in terms of price. Lab-grown diamonds can be anywhere from 20-40% less expensive than mined diamonds simply because of their shorter supply chain. CZs carry very little market value and can usually be anywhere from $30-$200 depending on the size. CZs are a great alternative to more expensive stones when you’re tight on budget or looking for a placeholder for a lab or mined diamond.


Mined Diamonds

Made from Carbon

Mohs Hardness Level = 10

Refractive Index = 2.42

Lab Grown Diamonds

Made from Carbon

Mohs Hardness Level = 10

Refractive Index = 2.42

Cubic Zirconia

Made from Zirconium Dioxide

Mohs Hardness Level = 8.25

Refractive Index = 2.2

man-made ring on finger

Benefits of Lab-Grown Diamonds

If you’re looking for something that is more affordable, yet of the same quality as mined diamonds, lab-grown diamonds are absolutely your best option for diamond jewelry.

As mentioned above, lab-grown diamonds can be significantly less than mined diamonds, without losing any of the value of the stone. This is allowing more couples to find the ring of their dreams, at a price they never dreamt possible. It’s also giving a lot more wiggle room in a budget to get a better diamond. For example, with the 20-40% savings, you could improve your desired diamond’s cut, color, or clarity.

Lab diamonds are also significantly less harmful to the environment. When you take into consideration all of the steps that must take place to move a diamond from deep within the earth, to your loved ones finger, it’s quite startling. From the giant gaping holes in the earth from the physical mining to the emissions and energy wasted from the equipment, it’s enough to make you stop and think. And, although lab-grown diamonds are not 100% free from impact, they are definitely a better option in terms of damage to our earth.

Finally, lab-grown diamonds are the only way to ensure a 100% ethically sourced diamond. Although there are many companies out there that claim their mined diamonds are “conflict-free," it’s almost impossible to know for sure if this is true. Tracking a singular stone from excavation all the way through the cutting, grading, and distribution processes, is extremely difficult and some companies have even been called out for their misleading promises in this regard.

Cubic zirconia vs. diamonds: When to choose a CZ

If you are looking to pledge your love and commitment, but your financials are a bit tighter than expected, go ahead and purchase a cubic zirconia ring for your significant other. There should be no shame in presenting the one you love with a gorgeous gemstone, even if it’s not a real diamond. Likely, the time will come, down the road, when you will be able to upgrade the ring. When it does, a man-made diamond will be the perfect choice to ensure an affordable, ethically sourced diamond, that will provide your partner with joy and peace of mind for years to come.


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