CZs are nothing like lab-grown diamonds.


In the world of gems and jewelry, few debates are as contentious as the comparison between cubic zirconia (CZ) and lab-grown diamonds. While both may share a certain sparkle, the idea that these two gems are remotely alike is, to put it bluntly, ridiculous. In this blog, we will dissect the glaring differences between cubic zirconias and lab-grown diamonds, emphasising why it is essential not to confuse the two.

Composition Matters

Let's start with the basics: what these gems are made of. Cubic zirconia is a synthetic crystalline substance composed of zirconium dioxide, whereas lab-grown diamonds are created using pure carbon atoms arranged in a diamond crystal lattice structure, just like natural diamonds. This fundamental difference in composition sets the stage for all the disparities that follow.

Hardness & Durability

One of the most significant differences between cubic zirconia and lab-grown diamonds is their hardness. Diamond is the hardest naturally occurring substance on Earth, ranking a perfect 10 on the MOHS scale of mineral hardness. Lab-grown diamonds share this exceptional hardness, making them incredibly durable and resistant to scratching. Cubic zirconia, on the other hand, ranks at about 8-8.5 on the MOHS scale, making it significantly softer and more prone to wear and tear. Over time, a CZ gem can easily become scratched and lose its lustre, while a lab-grown diamond maintains its brilliance.

Brilliance & Fire

The way light interacts with a gem is a crucial factor in its beauty. Diamonds, both natural and lab-grown, have a dazzling brilliance and fire that sets them apart from all other gemstones. This extraordinary play of light is a result of a diamond's exceptional refractive index and dispersion. Cubic zirconias, while reasonably sparkly, simply cannot compete with the mesmerising beauty of a diamond. CZ stones may exhibit flashes of colour, but they lack the depth and complexity of a diamond's fiery display.

Authenticity & Value

The value of a gemstone is not solely determined by its appearance but also by its authenticity and rarity. Lab-grown diamonds are real diamonds with the same chemical, optical, and physical properties as their natural counterparts. They are created under controlled conditions, making them more ethical and environmentally friendly. In contrast, cubic zirconias are essentially diamond simulants; they may look somewhat like diamonds but lack their intrinsic value. When it comes to investments or meaningful jewelry pieces, authenticity and value matter, and CZ falls short in this regard.

Price Disparity

Another aspect where CZ and lab-grown diamonds differ significantly is their price. Cubic zirconias are incredibly affordable, making them an attractive option for costume jewelry or short-term use. Lab-grown diamonds, while more budget-friendly than natural diamonds, still command a higher price due to their authenticity and superior qualities. Cubic zirconias simply cannot compare to the value that lab-grown diamonds offer because the price of a gem is a reflection of its rarity and quality.


In conclusion, claiming that cubic zirconias are like lab-grown diamonds is a misconception that needs to be dispelled. While both may have some superficial similarities, their differences in composition, hardness, brilliance, authenticity, and value are substantial. Lab-grown diamonds stand as a genuine, ethical, and valuable alternative to natural diamonds, whereas cubic zirconias are primarily used for costume jewelry and lack the timeless beauty and durability of their diamond counterparts.

So, next time you come across someone comparing these two gems, remember that it's not just apples and oranges—it's more like comparing a shiny pebble to a precious gemstone. The choice between cubic zirconia and lab-grown diamonds ultimately comes down to your preferences, budget, and the purpose for which you're acquiring them. Just don't fall for the lie that they are comparable or interchangeable in any way.

August 21, 2023 — Jana Neill