Some people say that it’s really hard for a non-expert to tell cubic zirconia from a real diamond, but is this really true? In fact, there a lot of telltale signs that can indicate what stone you are dealing with.
A popular substitute for diamond, cubic zirconia is made of a synthetic material that is not as hard as the real thing. On the Mohs scale of hardness, cubic zirconia has a value of 8.5 while diamond is 10. In addition, cubic zirconia is not as resistant to heat as diamonds and can easily crack and burn under high temperature.
Let’s take a look at the most salient characteristics on which cubic zirconia differs from diamond:
1. No Inclusions
One of the most important differences between cubic zirconia and diamond is that cubic zirconia is virtually flawless. Since it is created artificially, cubic zirconia doesn’t have any inclusions. So, if you take a close look at such a stone and don’t see any black spots, lines or other imperfections inside, it is likely not a real diamond.
2. Prone to Scratching
Another characteristic of cubic zirconia is that it is less durable than diamond. Since cubic zirconia scratches more easily, with time, it starts to look worn. You should also keep in mind that this stone is more brittle than diamond and is therefore more prone to chipping, so handle it with care. Of course, since cubic zirconia is cheap, you can always buy a new stone when the one you have gets damaged or scratched.
3. Colorless but Fiery
Cubic zirconia is purely colorless and does not have any tints present in the stone. Its color corresponds to that of a diamond with the highest color grade. Therefore, if you buy cubic zirconia, you don’t need to worry about seeing any hints of yellow in it.
Although it is colorless, cubic zirconia exhibits very intense play of light. A good way to tell cubic zirconia from a diamond is to look at the flashes produced by the stone when light enters it. Cubic zirconia shines in all colors of the rainbow and has brilliance that is a lot more colorful than that of a real diamond.
4. Heavier than Diamond
Cubic zirconia weighs more than diamond. For instance, if you have two stones of approximately the same size, and one is cubic zirconia and the other is a diamond, the cubic zirconia will be noticeably heavier (about twice as heavy).
5. Smooth Edges
If you take a close look at a diamond’s facets, you will notice that their edges are very sharp. In contrast, the facets of a cubic zirconia stone have smoother and rounder edges. To spot this difference, though, you will need to look at the stones using a loupe, preferably one that has 10x magnification.
6. Cheap Settings
Since cubic zirconia is cheap, it is also often set in cheap mountings. For example, you will most likely find cubic zirconia in gold plated and gold filled jewelry instead of solid gold pieces. If you do find cubic zirconia set in solid gold, it is unlikely that the alloy’s purity will be higher than 10 karats.
7. Heat Insulator
Cubic zirconia is a better thermal insulator than diamond. Since diamond has higher thermal conductivity, if you breathe on the stone, the fog from your breath will disappear right away. If you do the same test with cubic zirconia, the stone will remain foggy for a longer time, indicating that you are not dealing with a real diamond.
The Ultimate Test
If you are still unsure whether your stone is cubic zirconia and want to be 100% certain, take it to a jewelry store. Jewelers usually have diamond testers, which are small electronic devices that can detect diamond, and if you ask to have your stone tested, you can find out the truth immediately, for a small fee.For more information on diamonds: Read our Diamond Cut Quality Guide.
Important: We recommend that you only buy diamonds that you have seen and examined in detail. Each diamond is unique, and a mere description of color, cut and clarity is not sufficient, as even stones of the same grades might look different.