Moissanite vs Lab-Grown Diamond: What's the Difference?
TL;DR: Moissanite and lab-grown diamond are different materials with different optical properties, not the same thing sold under two names. Moissanite is harder to obtain a truly colourless stone in, throws more rainbow-coloured fire than diamond (which some people love and others find distracting), and costs a fraction of even a lab-grown diamond. We work exclusively with certified diamonds, natural and lab-grown, and don't offer moissanite — here's an honest comparison either way.
What Moissanite Actually Is
Moissanite is silicon carbide, a naturally occurring mineral so rare that virtually all moissanite sold today is lab-created rather than mined. It was first identified in 1893 in meteorite fragments, and lab production has made it commercially available since the 1990s as a diamond alternative.
Moissanite vs Lab-Grown Diamond: The Real Differences
These are not the same material wearing different labels — they're chemically distinct, and that produces real optical differences:
| Factor | Moissanite | Lab-Grown Diamond |
|---|---|---|
| Hardness (Mohs) | 9.25 | 10 |
| Fire (rainbow flashes) | Very high — more than diamond | Balanced, considered the benchmark |
| Colour | Can show a faint grey or yellow tint, especially in larger stones | Available truly colourless (D–F) at any size |
| Cost | Lowest of the three | 60–80% less than natural, still a genuine diamond |
| Certification standard | Varies by retailer | GIA / IGI, same standard as natural |
The fire difference is the most noticeable in person: moissanite throws more visible rainbow colour in its sparkle than diamond does. Some people find this beautiful and distinctive; others find it looks less like a "real diamond" and more obviously synthetic, precisely because it doesn't match the sparkle people are used to seeing.
Why We Don't Offer Moissanite
We focus exclusively on certified diamonds — natural and lab-grown — because that's where our sourcing relationships, certification standards, and expertise are built. This isn't a judgement on moissanite as a material; it's simply not what we specialise in. If cost is the primary driver behind considering moissanite, a lab-grown diamond is worth comparing directly: it's a genuine diamond, not an alternative material, and the price gap to moissanite is smaller than most people expect once you're comparing similar carat weights and quality.
If You're Choosing Between Them
Choose moissanite if minimising cost is the absolute priority and the distinctive rainbow fire appeals to you rather than concerns you. Choose lab-grown diamond if you want the material, optical performance, and certification standard of a genuine diamond, at a cost still dramatically below natural. See our natural vs lab-grown guide for the full picture on diamond options.
Choosing at À Vie Diamonds
We're happy to talk honestly about how lab-grown diamond compares to moissanite if you're weighing up the options — get in touch to discuss your budget and priorities.
Frequently Asked Questions
Is moissanite the same as a lab-grown diamond? No. Moissanite is silicon carbide, a different material entirely, with different hardness, fire, and optical properties to diamond.
Is moissanite cheaper than lab-grown diamond? Yes, typically significantly cheaper — though a lab-grown diamond costs far less than most people expect once compared directly.
Does À Vie Diamonds sell moissanite? No — we work exclusively with certified natural and lab-grown diamonds.
Last reviewed: July 2026 · À Vie Diamonds