What is the difference between lab diamonds and cubic zirconia?
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’s’.
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 important to discuss the difference in 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 diamond alternative if you’re tight on budget or looking for a placeholder for a lab or mined diamond.