A lot of people think that lab-grown diamonds and cubic zirconia are the same stones. Although they look similar (definitely not the same), these two stones are completely different. Lab-grown diamonds vs cubic zirconia – let’s go into details and see what they are made of and how you can tell the difference.
What are Lab-Grown Diamonds Made Of?
Lab-grown diamonds, also known as synthetic diamonds, man-made diamonds, cultured or cultivated diamonds, have the same chemical composition and physical properties as natural diamonds. The only difference is that they are created synthetically in labs.
Lab-grown diamonds are not considered fake just because they are made artificially. They are still real diamonds.
What is Cubic Zirconia Made Of?
Cubic zirconia is a synthetically created stone which is a form of zirconium dioxide. These stones are usually colourless and relatively clean (flawless).
Since they have similar optical and physical properties to diamonds, they are often used as diamond simulants.
Lab-Grown Diamonds vs Cubic Zirconia
Lab-grown diamonds and cubic zirconia are completely different in terms of physical and chemical properties.
Lab-grown diamonds are much more durable than cubic zirconia. While synthetic diamonds are rated 10 on the Mohs scale of hardness (same as natural diamonds), cubic zirconia is rated 8.5. For this reason, cubic zirconia is less durable, easier to scratch and break than cultivated diamonds.
Facets and Cut
Since cubic zirconia is softer than man-made diamonds, these two stones differ in how sharp the edges of their facets are when cut and polished.
Lab-grown diamonds, like natural ones, have very sharp facet edges, while cubic zirconia has more rounded edges, and with time, they become even more rounded.
Another significant difference between cubic zirconia and synthetic diamonds is the level of their dispersion. This property is related to how a stone breaks down light into rainbow flashes.
Cubic zirconia has higher dispersion (0.058-0.066) than a diamond (0.044), and for this reason, when exposed to light, it exhibits flashes that are more colourful than those of cultivated diamonds.
Cubic zirconia is heavier than diamond. If you weigh cubic zirconia and compare its weight with that of a lab-grown diamond of the same size, the first would be significantly heavier.
Although synthetic diamonds are cheaper than natural ones, they are still significantly expensive compared to cubic zirconia.
Cubic zirconia costs a fraction of the price of a lab-grown diamond of the same carat weight, colour and clarity.
Heat and Electric Conductivity
Lab-grown diamonds and cubic zirconia completely differ in the way they conduct heat and electricity. The easiest way to tell them apart is by using a diamond tester. This tool measures the conductive properties of materials.
However, it is important to mention that most diamond testers will indicate whether a stone is a diamond, but if it is not, they won’t tell you whether it’s cubic zirconia or something else.