Moissanite vs. Lab-Grown Diamond: Which Engagement Ring Stone Is Right for You?

by Designs by KNR October 29, 2026

If you're shopping for an engagement ring today, two stones come up again and again: moissanite and lab-grown diamond. Both are beautiful, both are durable enough for everyday wear, and both cost far less than a mined diamond of the same size. But they are not the same thing. After three generations in the jewelry business, here's how we explain the difference to our own customers.

What they are

Lab-grown diamonds are real diamonds. They're made of pure carbon with the same crystal structure as a mined diamond, so they have the same hardness, brilliance and chemistry. The only difference is where they formed: in a laboratory over weeks instead of underground over millions of years.

Moissanite is a different gemstone entirely. It's silicon carbide, first discovered in a meteor crater and now created in labs. It isn't a diamond and isn't trying to be. It's a brilliant gem in its own right.

Sparkle: fire vs. brilliance

This is where most people notice the difference. Moissanite has a higher refractive index than diamond (about 2.65 vs. 2.42) and more than twice the dispersion. In plain terms, moissanite throws off more fire, those flashes of rainbow color, especially in sunlight. Diamonds show more white brilliance with softer flashes of color.

Neither is better. Some people love moissanite's lively, colorful sparkle; others prefer the classic look of a diamond. If you can, look at both in natural light.

Durability

Diamond is the hardest gemstone at 10 on the Mohs scale. Moissanite is close behind at 9.25, harder than sapphire and ruby, and well suited to an engagement ring you'll wear every day for decades. Both hold their polish and resist scratching far better than most gemstones.

Color and clarity

Our moissanite is colorless (D-F) with VVS clarity, the top of the color and clarity scales. Our lab-grown diamond center stones are IGI certified and graded for color, clarity and cut, so you know exactly what you're getting. (Not sure what IGI means? Read our guide to IGI vs. GIA certification.)

Price

Moissanite is the most budget-friendly of the two. For the price of a modest lab-grown diamond, you can often choose a much larger moissanite. Lab-grown diamonds cost more than moissanite but significantly less than a mined diamond of similar size and quality.

So which should you choose?

Choose moissanite if you want the biggest, brightest look for your budget and love extra fire and color in your sparkle.
Choose a lab-grown diamond if it matters to you that the stone is a diamond, with a grading report to match.
Choose a natural diamond if you want an earth-mined stone with GIA certification.

Every ring we make is set in solid 14K gold, and most designs are available with any of these stones.

Shop by stone

Still deciding? Contact us or call 310-486-8838 (daily, 9am–7pm Pacific). We're happy to talk you through it.