ARVENIER
Moissanite is a gem made of silicon carbide. Natural moissanite is extremely rare, so the moissanite used in jewellery is created in a laboratory. It is very hard (about 9.25 on the Mohs scale), shows strong flashes of colour, and is a different material from diamond, not a type of diamond.
Where moissanite comes from
The mineral is named after French chemist Henri Moissan, who identified tiny crystals of silicon carbide in material from the Canyon Diablo meteorite crater in Arizona in the 1890s. Natural crystals are far too small and scarce for jewellery. Gem-quality moissanite became commercially available in the late 1990s, once laboratories could grow larger, clear crystals.
So when you see “moissanite” on a jewellery listing, it means a laboratory-created stone. That is a normal and expected description, not a warning sign.
How hard and durable is it?
At around 9.25 on the Mohs scale, moissanite is harder than sapphire and ruby (9) and second only to diamond (10) among common gem materials. In everyday wear that means it resists scratching well. Hardness is not the same as toughness, though: any stone can chip if it takes a sharp knock at the wrong angle, so treat a moissanite piece with ordinary care.
Why it sparkles differently from diamond
- More “fire”: moissanite splits light into colours more strongly than diamond, so it often shows rainbow flashes, especially in sunlight.
- Double refraction: light is split into two rays inside the stone. Under magnification you may see facet edges appear doubled.
- Brilliance: its refractive index is higher than diamond’s, which contributes to a bright, lively look.
None of these makes it better or worse than diamond; they make it look different. Some people love the extra colour; others prefer diamond’s cooler white sparkle.
Moissanite and diamond testers
Moissanite conducts heat in a way similar to diamond, so simple heat-based “diamond testers” can read it as diamond. Testers that also measure electrical conductivity, and gemmological laboratories, can tell the two apart. If identity matters to your purchase, rely on the seller’s written description and any accompanying laboratory documentation rather than a pocket tester.
What to check on a moissanite listing
- Stone size, in millimetres or carats.
- Colour description (many moissanite stones are sold as colourless, near-colourless or faintly tinted).
- The metal and any plating used for the setting and chain.
- Whether any report or certificate is included, and who issued it.
- Care instructions and the return policy.
If any of these is missing, ask before you buy. For a side-by-side look at the two materials, read our guide Moissanite vs diamond: what are you actually comparing?
Frequently asked questions
Is moissanite a fake diamond?
No. It is its own gem material with its own properties. It becomes misleading only if it is sold as diamond.
Is moissanite the same as lab-grown diamond?
No. Lab-grown diamond is carbon with diamond’s crystal structure. Moissanite is silicon carbide.
Does moissanite get cloudy?
The stone itself does not cloud with normal wear. Lotion, soap and skin oils can dull any stone’s surface; warm water, a drop of mild soap and a soft brush restore the shine.