Lab-Grown Moissanite vs Diamond — What Is the Difference?

If you have been shopping for a premium watch or piece of jewellery, you have likely come across moissanite — a lab-grown gemstone that rivals diamond in almost every measurable way. But what exactly is the difference? And which one makes more sense in 2026?

What Is Moissanite?

Moissanite is a gemstone composed of silicon carbide (SiC). It was first discovered in 1893 by French chemist Henri Moissan in a meteor crater in Arizona — which is fitting, given its otherworldly sparkle. Natural moissanite is extraordinarily rare, so virtually all moissanite used in jewellery today is lab-grown.

And that is a good thing. Lab-grown moissanite is chemically identical to natural moissanite, produced under controlled conditions that ensure consistent quality, ethical sourcing, and a fraction of the environmental impact of diamond mining.

Moissanite vs Diamond: Head to Head

Why Moissanite Sparkles More Than Diamond

One of the most surprising facts about moissanite is that it actually outperforms diamond in brilliance and fire. Its refractive index of 2.65–2.69 exceeds diamond's 2.42, which means moissanite bends more light, producing more sparkle. Its dispersion (fire) of 0.104 is more than double that of diamond (0.044), resulting in vivid rainbow flashes that catch the eye.

For watch bezels, this matters enormously. A moissanite-set bezel catches light with every wrist movement, creating a display that is genuinely eye-catching in ways that smaller diamonds at the same price point simply cannot match.

Durability: Nearly Diamond-Hard

At 9.25 on the Mohs hardness scale, moissanite sits just below diamond (10) and well above sapphire (9). This means it resists scratches exceptionally well — you can wear a moissanite-set watch every day without worrying about the stones dulling or scratching. For practical purposes, moissanite is as durable as you need a gemstone to be.

The Ethical Argument

Lab-grown moissanite sidesteps the ethical concerns associated with diamond mining entirely. There are no mines, no environmental disruption, and full traceability from lab to finished product. For a growing number of European consumers, this is not just a bonus — it is a requirement.

Paul Rich Moissanite Collection

The Moissanite Frosted Star Dust II collection features trapezoid-cut lab-grown moissanite stones set into the bezel, paired with genuine blue aventurine dials and our signature frosted finish. Available from €849 in gold, silver, black, and rose gold.