Is Moissanite a Real Diamond? Real, Fake or Something Else
No. Moissanite is not a diamond, natural or lab grown. But it is not a fake either. Moissanite is a real gemstone in its own right: a different mineral that happens to look a lot like diamond. Here is what that means, why the two get mixed up, and how to be sure you always know which stone you are buying.
The short answer
A diamond is made of carbon, with its atoms arranged in a cubic crystal. Moissanite is made of silicon carbide, with a hexagonal crystal. They are different materials, so moissanite can never be a diamond, however similar the two look in a ring.
The US Federal Trade Commission's Jewelry Guides define a diamond as "a mineral consisting essentially of pure carbon crystallized in the isometric system", and say that using the plain word diamond for anything else is deceptive. That is why we never call moissanite a diamond, and why the phrase "moissanite diamond", which you will still see on some sites, is misleading.
Real, fake, simulant, lab grown: what the words mean
- Natural diamond: carbon, formed deep in the earth over millions of years and mined.
- Lab grown diamond: carbon with the same crystal structure as a natural diamond, grown in a lab in weeks. It is a real diamond, just not a mined one. See our lab grown diamond guide.
- Moissanite: silicon carbide. Henri Moissan found tiny natural crystals in 1893 in samples from Meteor Crater in Arizona, where the Canyon Diablo meteorite fell, but natural moissanite is far too rare and small for jewelry. Every moissanite you can buy is lab-created.
- Simulant: any material used to imitate the look of another gem. Moissanite, cubic zirconia, white sapphire and glass can all be used as diamond simulants. The word describes the job the stone does, not its quality.
- Fake: something sold as what it is not. Moissanite sold as moissanite is honest. Moissanite sold as diamond is fake, and that is the seller's fault, not the stone's.
Moissanite and diamond side by side
| Moissanite | Diamond | |
|---|---|---|
| Material | Silicon carbide | Carbon |
| Crystal system | Hexagonal | Cubic |
| Hardness (Mohs) | 9.25 | 10 |
| Refractive index | 2.65 to 2.69 | 2.42 |
| Dispersion (fire) | 0.104 | 0.044 |
| Specific gravity | about 3.22 | about 3.52 |
| Refraction | Double | Single |
| Jewelry stones come from | Labs only | Mines or labs |
For what these numbers mean when you wear the stone, read what is moissanite?
Why people mistake moissanite for diamond
- The look: colorless moissanite is bright, clear and cut in the same shapes as diamond, so at arm's length most people cannot tell them apart.
- The tester: many basic diamond testers only measure heat flow, and moissanite carries heat much like diamond, so it can read as diamond. Testers that also check electrical conductivity can usually separate them. See does moissanite pass a diamond tester?
- The wording: listings that say "moissanite diamond" or "lab diamond" for moissanite blur the line on purpose. Read the stone name, not the headline.
The differences you can see, such as stronger rainbow fire and doubled facet edges under a loupe, are explained in how to tell moissanite from diamond.
Is moissanite worse than diamond?
It is different, not lesser. Moissanite shows more colorful fire, costs far less than a diamond of the same size and is hard enough for a ring worn every day. Diamond is harder, has a whiter sparkle, and natural diamonds have a long-established resale trade. Which one is better depends on the look you love and the budget you have. We set out both sides in is moissanite worth it? and moissanite vs lab grown diamond.
How to be sure what you are buying
- Check the stone name on the product page and the invoice. It should say moissanite, lab grown diamond or natural diamond in plain words.
- Be wary of mixed names such as "moissanite diamond", "simulated diamond" without the actual material, or "lab diamond" on a moissanite listing.
- Read certificates carefully. Moissanite cards are usually issued by the seller or the stone's maker rather than by an independent gem lab, so treat them as a description, not proof. For a lab grown diamond, ask whether it has a report from an independent lab and check the report number on that lab's own website.
- Ask for the details: stone size in millimetres, color and clarity grades, metal and stamp.
- When in doubt, test it. A jeweler with a multi-tester, or a gem lab, can identify moissanite quickly.
At Bhumi Gems every moissanite is sold as moissanite and every lab grown diamond as a lab grown diamond, with the stone named in the product description. Browse moissanite engagement rings, loose moissanite stones or our moissanite vs diamond guide.
Quick answers
Is moissanite a fake diamond?
It is not a diamond at all, but it is a real gemstone. It only becomes a "fake" if someone sells it as a diamond.
Is moissanite a lab grown diamond?
No. Both are made in labs, but a lab grown diamond is carbon and moissanite is silicon carbide.
Is moissanite natural?
It does occur in nature, but only as tiny, very rare crystals. All moissanite used in jewelry is lab-created.
Can a jeweler tell my ring is moissanite?
Yes. With a loupe and a multi-tester most jewelers can identify it in minutes.
Can moissanite be called a diamond?
No. In the US, the FTC Jewelry Guides reserve the word diamond for stones made of crystallized carbon. Moissanite should always be sold under its own name.