Moissanite vs Cubic Zirconia vs Lab-Grown Diamond
If you want a bright, colourless stone that costs less than a mined diamond, three names keep coming up: moissanite, cubic zirconia and lab-grown diamond. They can look alike in a photo, but they are very different materials. (Comparing moissanite with mined diamond? Read moissanite vs diamond.)
The quick answer
- Cubic zirconia is the budget option: bright when new, but softer, and it scratches and clouds over time.
- Lab-grown diamond is real diamond made in a lab: the hardest of the three, and usually the most expensive for the same size.
- Moissanite sits in between: nearly as hard as diamond, with more fire, at a much lower price than diamond.
Side by side
| Moissanite | Cubic zirconia | Lab-grown diamond | |
|---|---|---|---|
| What it is | Silicon carbide | Zirconium dioxide | Carbon (diamond) |
| Origin | Lab-created | Lab-made | Lab-grown |
| Hardness (Mohs scale) | 9.25 | about 8–8.5 | 10 |
| Sparkle | Very bright, strong rainbow fire (dispersion about 0.104) | Bright when new | Classic diamond sparkle (dispersion about 0.044) |
| Over time | Stays bright with simple cleaning | Scratches and clouds | Stays bright with simple cleaning |
| Basic thermal diamond tester | Often reads as diamond; a multi-tester identifies it | Does not read as diamond | Reads as diamond |
| Price for the same look | Much less than diamond | Lowest | Usually the highest of the three |
Moissanite vs cubic zirconia
On a budget, this is the comparison that matters most. Both stones are made in a lab and both look bright on day one. The difference shows over months and years: cubic zirconia is softer, about 8–8.5 on the Mohs scale, so it picks up fine scratches and its surface clouds over time. Moissanite, at 9.25, keeps its polish and stays bright with simple cleaning, and it shows noticeably more rainbow fire. If you want a ring or studs to wear every day for years, moissanite is the more durable choice.
Moissanite vs lab-grown diamond
A lab-grown diamond is chemically and physically diamond, grown in a lab instead of mined. It is the hardest of the three (10 on the Mohs scale) and has the classic, whiter diamond sparkle. Moissanite is a different gemstone: slightly less hard, with more colourful fire, roughly 10% lighter at the same size, and doubly refractive where diamond is singly refractive. Lab-grown diamonds have come down in price, but for the same visible size moissanite usually still costs considerably less. The choice comes down to what matters more to you: the material itself, or the look and the budget.
Which should you choose?
- Choose moissanite for a hard-wearing, very sparkly stone at a price that makes bigger or more detailed designs affordable.
- Choose lab-grown diamond if it has to be diamond and the budget allows.
- Choose cubic zirconia for costume or occasional jewelry, where long-term wear matters less.
We work with moissanite and sell it as moissanite. To see it in classic designs, start with the Round Moissanite Ring (from €69.90), the Halo Moissanite Engagement Ring (€74.90), the Solitaire Moissanite Studs (from €49.90) or the Moissanite Tennis Bracelet (from €119.90). Or browse all moissanite jewelry.
Read next: is moissanite real? and does moissanite pass a diamond tester?