Moissanite gets grouped with lab-grown diamonds often enough that a lot of shoppers assume they're the same thing, or at least close cousins. They're not. Moissanite is a completely different mineral with its own optical signature, price point, and durability profile. If you're deciding between the two for an engagement ring or an everyday piece, here's what actually separates them.
What Is Moissanite?
Moissanite is a silicon carbide gemstone, originally discovered in trace amounts in a meteor crater and now produced entirely in labs for jewelry use. It was never naturally mined at commercial scale; virtually all moissanite in circulation today is lab-created. That's a key distinction from lab-grown diamonds, which are chemically identical to natural diamonds. Moissanite is chemically distinct from diamond entirely.
How They Compare
Brilliance and Fire
Moissanite has a higher refractive index than diamond, which means it bends light more and produces more visible flashes of color, sometimes described as a rainbow or disco-ball effect in direct light. Diamonds, lab-grown or natural, return more white light and less colored flash, which most people associate with a more classic diamond look. Which reads as more attractive is genuinely a matter of preference.
Hardness
Diamond is a 10 on the Mohs hardness scale, the hardest natural material known. Moissanite is a 9.25, still extremely durable and suitable for daily wear, but measurably softer than diamond. In practice, both hold up well to normal use; diamond has a slight edge in long-term scratch resistance.
Price
Moissanite is significantly less expensive than either lab-grown or natural diamond, often a fraction of the cost for a stone of comparable visual size. If budget is the primary constraint and you're comfortable with moissanite's distinct sparkle, it stretches furthest.
Origin and Certification
Diamonds, lab-grown or natural, are graded against the 4Cs and certified by labs like IGI or GIA. Moissanite is typically sold by millimeter size rather than carat weight and graded on a simpler quality scale, since it doesn't carry the same certification infrastructure diamonds do.
Which Should You Choose?
If you want the closest possible experience to a traditional diamond, in look, certification, and resale familiarity, lab-grown diamond is the better match, and it's priced meaningfully below natural diamond already. If maximizing size and sparkle on a tighter budget is the priority, and you like moissanite's more colorful flash, it's a legitimate and durable option in its own right. Neither is a compromise; they're simply different stones with different strengths.
What We Offer
We work exclusively in IGI-certified lab-grown and natural diamonds rather than moissanite, so every center stone we sell is independently graded against the same 4Cs standard. If you've decided lab-grown diamond is the direction you want, our lab-grown vs. natural diamond guide covers that comparison in full.
FAQ
Is moissanite a type of lab-grown diamond?
No. Moissanite is a chemically distinct mineral (silicon carbide), while lab-grown diamonds are chemically identical to natural diamonds (pure carbon). They're often shopped side by side but are not the same material.
Does moissanite look fake next to a diamond?
It doesn't look fake, but it looks different. Moissanite produces more colorful flashes of light due to its higher refractive index, while diamonds return more white brilliance. Trained eyes and some laypeople can tell them apart in direct sunlight.
Is moissanite cheaper than a lab-grown diamond?
Yes, generally significantly cheaper for a stone of comparable visual size, since moissanite is more abundant to produce and doesn't carry the same certification and grading infrastructure as diamonds.
Which is more durable, moissanite or diamond?
Diamond, at 10 on the Mohs hardness scale versus moissanite's 9.25. Both are durable enough for daily wear, including an engagement ring, but diamond has a slight long-term edge in scratch resistance.
Browse our IGI-certified Lab-Grown Diamond Rings and Engagement Rings collections to compare stones side by side.