Is Moissanite a Real Diamond? Honest Answers Before You Buy

If you are shopping for an engagement ring, you have probably seen moissanite rings that look just like diamonds for a fraction of the price – and wondered what the catch is. The short answer: moissanite is not a diamond, but it is a real gemstone. It is not glass, not cubic zirconia and not a “fake”. It is its own mineral with its own strengths. Here is everything you need to know before you buy.

What is moissanite?

Moissanite is silicon carbide (SiC). It was first identified in 1893 by French scientist Henri Moissan in fragments of a meteorite crater in Arizona, which is why it is sometimes called “the gem from the stars”. Natural moissanite is far too rare to use in jewelry, so every moissanite you see in rings today is created in a lab, where it is grown as a crystal and then cut and polished like any other gemstone.

A diamond, by contrast, is pure carbon. A lab grown diamond is still a diamond – it has the same carbon crystal structure as a mined diamond – while moissanite is a completely different material.

Moissanite vs diamond at a glance

• Material: moissanite is silicon carbide; diamond (mined or lab grown) is carbon.
• Hardness: moissanite is 9.25 on the Mohs scale; diamond is 10. Moissanite is harder than sapphire and ruby, so it is very well suited to everyday wear.
• Sparkle: moissanite has a higher refractive index and more dispersion than diamond, so it throws more colorful “rainbow” flashes (fire). Diamond shows more white sparkle (brilliance).
• Price: moissanite costs far less than a diamond of the same size – usually a small fraction of a mined diamond, and noticeably less than a lab grown diamond.
• Origin: both moissanite and lab grown diamonds are created without mining.

Can people tell moissanite from a diamond?

To most people at normal viewing distance, a well-cut moissanite looks like a diamond. Up close, especially in bright sunlight, the extra rainbow fire is the main giveaway – many people actually prefer that look. Jewelers can tell them apart with a moissanite tester or under magnification, because moissanite is doubly refractive and diamond is not. Standard “diamond testers” that only measure heat can mistake moissanite for diamond, which is why jewelers use electrical-conductivity testers to check.

Is moissanite durable enough for an engagement ring?

Yes. With a hardness of 9.25, moissanite resists scratches extremely well and will keep its polish for decades of daily wear. It is also very tough and heat resistant. Like any gemstone, it can chip if it takes a hard knock at the wrong angle, so a secure setting – such as a bezel set moissanite ring – is a smart choice if you work with your hands.

Does moissanite get cloudy or change color?

Moissanite itself does not turn cloudy. If a moissanite ring starts to look dull, it is almost always lotion, soap or skin oil on the stone. A quick clean with warm water, a drop of mild dish soap and a soft toothbrush brings the sparkle straight back. See our jewelry care guide for step-by-step tips.

Moissanite or lab grown diamond: which should you choose?

Choose moissanite if you want the biggest, most fiery look for your budget and love colorful sparkle. Choose a lab grown diamond if you want a real diamond with classic white brilliance and a hardness of 10, while still paying much less than for a mined diamond. Both are ethical, both are durable, and both look stunning in solid gold or platinum. Our full moissanite vs lab grown diamond vs diamond comparison goes deeper into sparkle, color and price.

How to buy a moissanite ring with confidence

• Pick the shape first. Ovals, pears and elongated cushions look larger for their size; rounds give the most sparkle. Browse oval moissanite engagement rings or round moissanite rings.
• Choose a quality metal. Solid 14K or 18K gold and platinum last a lifetime; 925 sterling silver is a beautiful lower-cost option.
• Check the ring size. Use our ring size guide – it even has tips for a surprise proposal.
• Buy from a jeweler with clear policies. Every Claire Diamonds piece is handcrafted to order with free insured US shipping and easy 30-day returns.

Frequently asked questions

Is moissanite a fake diamond?

No. Moissanite is a genuine gemstone in its own right, not an imitation. It simply is not a diamond, because it is made of silicon carbide rather than carbon.

Will moissanite pass a diamond tester?

Basic thermal diamond testers can read moissanite as diamond, but electrical-conductivity testers and gemologists can tell the difference easily.

Does moissanite last forever?

With a hardness of 9.25 and no tendency to cloud, moissanite is made to be worn every day for a lifetime and can be passed down as an heirloom.

Is moissanite cheaper than a lab grown diamond?

Yes. For the same size and shape, moissanite is typically less expensive than a lab grown diamond, which is itself much less expensive than a mined diamond.

Ready to find yours? Explore all moissanite engagement rings or start a custom design with our team.