How does moissanite compare to natural and lab grown diamonds?

Moissanite is silicon carbide with a 9.25 Mohs hardness and 2.65 refractive index. Natural and lab grown diamonds are both carbon, with a 10 Mohs hardness and 2.42 refractive index. Moissanite throws more dramatic rainbow flashes; diamonds return a crisper white sparkle. Moissanite costs a small fraction of a comparable natural diamond, and lab grown diamonds sit between the two. One practical difference: diamonds carry a full 4C grading report from GIA or IGI, and moissanite does not.

Does SVS Fine Jewelry still sell moissanite?

We are selling down our remaining moissanite and will not be reordering it. A curated group of loose stones and finished engagement rings is left, all on final clearance in our Oceanside showroom. Once those are gone our showroom will carry natural and lab grown diamonds only. Call (516) 766-2614 for current clearance pricing.

Is moissanite graded by GIA?

No. GIA does not issue grading reports for moissanite. Some moissanite is accompanied by a report from Harro Gem, and a good deal of it carries no independent report at all. Natural and lab grown diamonds are both fully graded on the 4Cs by GIA or IGI, and every lab grown report discloses the stone's origin. If you are comparing stones, that difference in documentation is worth weighing.

Why did SVS stop carrying moissanite?

Moissanite made sense for a long time. If you wanted size, a lab origin, and a price that did not require a second thought, it was the only stone that delivered all three. Then lab grown diamonds became affordable and answered every one of those reasons with an actual diamond: same carbon, same crystal structure, same Mohs 10 hardness, same classic white sparkle as a mined stone, plus a full 4C grading report and eligibility for our Lifetime Warranty on engagement rings. Moissanite was never eligible for that warranty. See how lab grown diamonds are made and graded.

Does moissanite pass a diamond tester?

Most standard diamond testers work by measuring thermal conductivity, and moissanite conducts heat closely enough to diamond that it frequently reads as diamond on a pen-style tester. That is exactly why a thermal tester on its own is not enough. A combination tester that also measures electrical conductivity separates the two, and a gemologist can confirm it outright. SVS is an American Gem Society Accredited Gem Lab, so if you are not certain what is in a ring you already own, bring it in and we will screen it while you wait. There is no obligation to buy anything.

Is moissanite a lab grown diamond?

No, and this is the most common mix-up we hear. Both are grown in a laboratory, but they are different materials. Moissanite is silicon carbide. A lab grown diamond is carbon, sharing the same chemical, physical and optical properties as a mined diamond, and it is graded on the 4Cs by GIA or IGI. Moissanite is not graded that way. If you started your search wanting a lab-created stone, lab grown diamonds are worth understanding before you decide.

Are moissanite stones real?

Moissanite is a real gemstone. It is not a diamond, and those two statements do not conflict. Moissanite is silicon carbide, a genuine mineral with its own optical and physical properties, hard enough for daily wear at 9.25 on the Mohs scale. What it is not is a diamond, and it should never be described or sold as one.

Does moissanite get cloudy over time?

No. Moissanite does not turn cloudy or lose brilliance with age. What people notice is surface buildup from lotion, soap and skin oils collecting around the setting, which dulls any stone including a diamond. It cleans off completely. Bring the piece in any time and we will clean it free, whether you bought it here or not.

Is moissanite expensive?

Moissanite costs a small fraction of a comparable natural diamond, which is the main reason it became popular. The comparison that matters now is against lab grown diamonds, which have come down far enough to sit much closer to moissanite than they once did, while still being a diamond with a full 4C grading report. Send us the specs on a stone you are weighing and one of our gemologists will tell you plainly what the difference is worth.

What Is Moissanite?

Q: Is moissanite a diamond?

No. Moissanite is silicon carbide, a separate mineral with its own optical and physical properties. Both natural and lab grown diamonds are carbon. Moissanite is a genuinely beautiful and durable gemstone, but it is chemically and structurally a different stone, and it should never be sold or described as a diamond.

Gemstone Education · SVS Fine Jewelry

Moissanite is a lab-created gemstone made of silicon carbide. It is not a diamond, which is pure carbon, but it is exceptionally brilliant and hard enough for daily wear: 9.25 on the Mohs scale against diamond's 10, with a higher refractive index that produces more rainbow fire.

It was discovered in 1893 by French scientist Henri Moissan in an Arizona meteor crater. Natural moissanite is vanishingly rare, so virtually all moissanite sold for jewelry today is grown in a laboratory.

Written by Sami V. Saatchi, GIA Graduate Gemologist and Founder of SVS Fine Jewelry, Oceanside NY.

Silicon Carbide A different mineral than diamond	9.25 Mohs Hardness — diamond is 10
2.65 RI Refractive index — diamond is 2.42	1893 Discovered by Henri Moissan

Most people researching moissanite are really asking a bigger question: which stone belongs in the ring. Below we cover where moissanite came from, how it compares to natural and lab grown diamonds on the measures that matter, and why we no longer carry it.

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The History of Moissanite

Moissanite was discovered in 1893 by French chemist Dr. Henri Moissan while examining rock fragments from a meteor crater in Diablo Canyon, Arizona. Initially mistaken for diamond, Moissan later identified the mineral as silicon carbide, a substance previously unknown in nature. It was named moissanite in his honor following his Nobel Prize in Chemistry in 1906.

Natural moissanite is exceptionally rare, found in only trace amounts in meteorites, kimberlite deposits, and as inclusions in other minerals. The natural supply is far too small to support commercial jewelry production. In 1995, North Carolina-based Charles & Colvard developed a process to grow gem-quality moissanite in laboratory conditions, making it available as a fine jewelry stone for the first time. Virtually all moissanite sold today is grown in a laboratory.

Moissanite vs Diamond: How They Compare

Moissanite is usually weighed against diamonds, both natural and lab grown, for engagement rings. They are different minerals with genuinely different properties, and the differences matter more in some places than others.

Property	Moissanite	Natural Diamond	Lab Grown Diamond
Composition	Silicon carbide	Carbon	Carbon
Is it a diamond?	No, a separate mineral	Yes	Yes
Hardness (Mohs)	9.25	10	10
Refractive index	2.65	2.42	2.42
Sparkle	High fire, rainbow flashes	Classic white sparkle	Classic white sparkle
Independent grading	Not graded by GIA. Some stones carry a Harro Gem report, others have none	Full 4C grading report from GIA	Full 4C grading report from GIA or IGI
SVS Lifetime Warranty	Not eligible	Eligible on engagement rings	Eligible on engagement rings
Relative price (1ct)	$	$$$$	$$

What Makes Moissanite Different

A higher refractive index, and more fire. Moissanite's refractive index of 2.65 is higher than diamond's 2.42, so it bends light more dramatically. The result is exceptional fire, the rainbow flashes you see when light hits the stone. Some people love that. Others find it reads as more rainbow than the classic white brilliance of a diamond, particularly above 1.5 carats.

Double refraction. Moissanite is doubly refractive, meaning light splits into two rays as it passes through the stone. Diamond is singly refractive, producing crisper white light return. The difference is subtle but visible to a trained eye, particularly in elongated cuts like emerald, oval, and marquise.

Durable enough for daily wear. At 9.25 on the Mohs scale, moissanite is the second-hardest gemstone used in jewelry, harder than sapphire, ruby, and emerald. It resists scratching and holds up to everyday wear.

An Honest Answer

Why We Stopped Carrying Moissanite

Moissanite made a lot of sense for a long time. If you wanted real size, a lab origin, and a price that did not require a second thought, it was the only option that delivered all three. We sold it for years and we stand behind every piece we sold.

Then lab grown diamonds became affordable, and every one of those reasons was answered by an actual diamond. Same size for the money. Same lab origin. Same carbon, same crystal structure, same Mohs 10 hardness, same classic white sparkle as a mined stone. Plus a full 4C grading report from GIA or IGI, and eligibility for our Lifetime Warranty on engagement rings, which moissanite never had.

So we stopped buying it. What is left in the case is on final clearance, and once it is gone our showroom will carry natural and lab grown diamonds only. If you are early in your search, we would rather you saw both side by side before deciding anything.

How lab grown diamonds are made and graded · Shop lab grown engagement rings

If You Already Own Moissanite

Nothing above is a reason to feel differently about a ring you already have. Moissanite is a genuinely beautiful, genuinely durable stone, and a ring means what it meant on the day it was given. If yours needs sizing, cleaning, a prong checked, or a setting repaired, bring it in. Our master jewelers work on it the same as anything else in the shop.

And if you are not sure what is in a ring you own or inherited, we can tell you. Our gem laboratory is on the premises and screening takes minutes.

SVS Fine Jewelry serves couples across Long Island — Oceanside, Long Beach, Rockville Centre, Lynbrook, Garden City, Merrick, Island Park, and all of Nassau County — as well as clients traveling from New York City, New Jersey, and Connecticut. Locally owned and locally loved since 2003, our 4,000+ sq ft Oceanside showroom offers expert guidance from GIA Graduate Gemologists across every stone option, with over 2,500 five-star reviews from the couples we have served.

If you cannot get to Oceanside, we will still help. Send us the specs of a stone you are considering and one of our GIA Graduate Gemologists will tell you plainly what you are looking at, whether or not you buy from us. Call (516) 766-2614 or send us a message.

The right stone for your engagement ring is the one that fits your story, your style, and your priorities. We help you see them all in person.

Not Sure What You Have

We Can Identify Your Stone While You Wait

If you own a ring and are not certain whether the center stone is moissanite, a diamond, or something else, bring it in. SVS is an American Gem Society Accredited Gem Lab, which means AGS has verified we maintain a gem laboratory on the premises with a credentialed gemologist and the equipment to use it. Screening takes minutes and there is no obligation to buy anything.

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Final Inventory

Our Remaining Moissanite — Final Clearance

A curated mix of finished engagement rings and loose stones remains, all on final clearance. Once these are sold, our showroom will carry natural and lab grown diamonds only. Shop online, or come in to see them in person and ask about current clearance pricing.

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Call (516) 766-2614

What Is Moissanite?

The History of Moissanite

Moissanite vs Diamond: How They Compare

What Makes Moissanite Different

Why We Stopped Carrying Moissanite

If You Already Own Moissanite

The Moissanite Engagement Collection

Natural Diamond Upgrade Program

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What Is Moissanite?

The History of Moissanite

Moissanite vs Diamond: How They Compare

What Makes Moissanite Different

Why We Stopped Carrying Moissanite

If You Already Own Moissanite

The Moissanite Engagement Collection

Natural Diamond Upgrade Program

5-Star Google Rating

Nationwide Warranty

Financing Available

Free Shipping on $75+

5-Star
Google Rating