“Is lab-grown the same as moissanite?” Jewellers hear that question every day. The answer is no. Moissanite, cubic zirconia and lab-grown diamond look similar at first glance, but they are three different materials. In this article we compare them side by side.
1. Three stones, three materials
Lab-grown diamond
A lab-grown diamond is made of pure carbon, with the same crystal structure as a natural diamond. Chemically and physically it is a diamond. Only its origin differs.
Moissanite
Moissanite is silicon carbide. It occurs very rarely in nature and is made in a laboratory for jewellery. It is a gemstone in its own right, not a diamond.
Cubic zirconia
Cubic zirconia is zirconium dioxide. It is an inexpensive synthetic stone used mainly as a diamond imitation in fashion jewellery.
2. The differences in a table
| Feature | Lab-grown diamond | Moissanite | Cubic zirconia |
|---|---|---|---|
| Material | Carbon (diamond) | Silicon carbide | Zirconium dioxide |
| Hardness (Mohs) | 10 | 9.25 | 8 to 8.5 |
| Refractive index | 2.42 | Approx. 2.65 | Approx. 2.15 |
| Sparkle | Bright white light and fire | Lots of rainbow colours | Less bright |
| Durability | Stays beautiful for a lifetime | Very good | Scratches and turns dull |
| Diamond tester | Diamond | Sometimes diamond on a thermal tester | Not diamond |
| Price | Highest of the three | Lower | Very low |
3. Hardness and wear
Diamond is the hardest natural material, with a 10 on the Mohs scale. Moissanite follows at 9.25 and is also very suitable for daily wear. Cubic zirconia is noticeably softer: after a few years of wear it gets small scratches and loses its lustre.
4. Sparkle: white light or rainbow
Moissanite refracts light more strongly than diamond. That produces lots of rainbow-coloured flashes, especially in sunlight. Some customers love it, others find it less natural. A diamond gives a balanced mix of bright white light and colourful fire. Cubic zirconia sparkles nicely at first, but loses that more quickly.
5. Identifying with a tester
A simple thermal diamond tester can sometimes indicate moissanite as diamond, because both conduct heat well. A tester that also measures electrical conductivity does make the distinction. A lab-grown diamond reads “diamond” on both types of tester.
6. What should you recommend to your customer?
- Lab-grown diamond for those who want a diamond, for an engagement ring or a piece for life, within a reasonable budget.
- Moissanite for those who want lots of sparkle at a low price and do not mind that it is not a diamond.
- Cubic zirconia for fashion jewellery and temporary use.
For jewellers the message is clear: lab-grown is a diamond, moissanite and cubic zirconia are alternatives. Read more about the difference from natural diamond in lab-grown vs natural diamond.
Frequently asked questions
Is moissanite the same as a lab-grown diamond?
No. Moissanite is silicon carbide, a different material. A lab-grown diamond is a diamond.
Which is more durable: moissanite or lab-grown diamond?
Both are very hard and suitable for everyday wear. With a 10 on the Mohs scale, diamond is the hardest.
Can a jeweller tell the difference?
An experienced jeweller often recognises moissanite by its double refraction and rainbow effect. With a suitable tester the difference can always be established.
Lab-grown diamonds in your collection
Noam Jewels supplies lab-grown diamond jewellery to jewellers across Europe: more than 1,500 designs in 14k and 18k gold, white label and delivered in 2 to 3 weeks. Create your B2B account or book a call.
Lab-grown jewellery for your collection
Straight from the Antwerp diamond district, exclusively for professional jewellers.
- 1,500+ designs in 14k and 18k gold
- Delivery in 2 to 3 weeks
- White label, under your own name
