Moissanite, explained.
More fire than a diamond, nearly as hard, grown without mining, and a fraction of the price. Here is what moissanite is, what it is not, and why so many people choose it.
What it is
Moissanite is a gemstone made of silicon carbide. It was first identified in 1893 by the French chemist Henri Moissan in fragments of a meteorite, and natural moissanite is so rare that the stones in jewelry today are grown in laboratories.
The result is a hard, brilliant, colourless stone that sparkles with more fire than almost any other gem.
What it is not
- Not a diamond. It is its own gemstone with its own properties, and we always call it moissanite.
- Not cubic zirconia or glass. Moissanite is far harder and far more brilliant than either.
- Not fake. It is a real gemstone, valued for exactly what it is.
Moissanite and diamond, side by side
| Moissanite | Diamond | |
|---|---|---|
| Brilliance (refractive index) | About 2.65–2.69 | About 2.42 |
| Fire (dispersion) | About 0.104 | About 0.044 |
| Hardness (Mohs scale) | 9.25 | 10 |
| Where it comes from | Grown in a lab, no mining | Mostly mined (lab-grown diamonds also exist) |
| Standard thermal diamond tester | Passes | Passes |
| Price for a similar size | A fraction of diamond | Much higher |
Higher refractive index means the stone bends light more, so it looks brighter. Higher dispersion means it splits light into more colour, the rainbow flashes known as fire.
The real numbers
How moissanite measures up against diamond and other popular stones. Every chart starts from zero, so the bars are honest.
Brilliance
Refractive index: how strongly a stone bends light. Higher looks brighter.
| Moissanite | 2.65–2.69 |
|---|---|
| Diamond | 2.42 |
| Cubic zirconia | 2.15–2.18 |
| Sapphire | 1.76–1.77 |
| Glass | about 1.5 |
Fire
Dispersion: how much a stone splits white light into rainbow colour.
| Moissanite | 0.104 |
|---|---|
| Cubic zirconia | 0.058–0.066 |
| Diamond | 0.044 |
| Sapphire | 0.018 |
Moissanite shows more than twice the fire of diamond.
Hardness
Mohs scale: resistance to scratching. Higher wears better.
| Diamond | 10 |
|---|---|
| Moissanite | 9.25 |
| Sapphire | 9 |
| Cubic zirconia | 8–8.5 |
| Glass | about 5.5 |
The Mohs scale is a ranking, not an even measure. Moissanite is the second-hardest gemstone used in jewelry.
Why choose moissanite
More sparkle
More brilliance and more than twice the fire of diamond, so it catches light from across the room.
Made to be worn
At 9.25 on the Mohs scale it is harder than sapphire and ruby, made for rings you never take off.
Grown, not mined
Gem moissanite is created in a lab, so no mining goes into the stone itself.
More for your budget
A fraction of the cost of a diamond of similar size, so you can choose the bigger, bolder piece.
Moissanite passes the standard thermal diamond tester. Testers that also check electrical conductivity can tell it apart, and we will always tell you exactly what you are buying.
What ethically sourced means
An ethically sourced stone is one whose path to you does not fund violence, exploit workers or tear up land and communities. Here is how the two journeys compare.
A mined diamond
- Dug from the earth
Large-scale mining moves enormous amounts of rock and land to recover a small amount of diamond.
- A troubled history
In the 1990s, diamonds mined in war zones such as Sierra Leone and Angola paid for brutal civil wars. They became known as conflict or blood diamonds.
- Certified, with gaps
Since 2003 the Kimberley Process has certified rough diamonds to keep conflict stones out of the market. Critics point out that it only covers diamonds that fund rebel groups, not wider abuses.
A moissanite stone
- Grown in a lab
Natural moissanite is extremely rare, so gem moissanite is created in a laboratory. No mine is dug for the stone.
- Cut and polished
The crystal is cut and polished into a finished gem, facet by facet, like any fine stone.
- Set and delivered to you
No conflict zone in the supply chain of the stone itself, and no mining scar behind your ring.
Lab-grown diamonds also avoid mining. Moissanite gives you that peace of mind with more fire, at a fraction of the price.
Moissanite questions
Want to see a stone up close? Buy online and we bring it to your door, or call 725-358-6231.
Is moissanite a real gemstone?
Yes. Moissanite is a real gemstone made of silicon carbide. It is not a diamond and it is not an imitation of one; it is its own stone, and we always call it moissanite.
Will moissanite pass a diamond tester?
Moissanite passes the standard thermal diamond tester, because it moves heat much like diamond does. Testers that also measure electrical conductivity can tell the two apart. We never sell moissanite as diamond.
Does moissanite sparkle more than diamond?
Yes. Moissanite bends light more strongly than diamond (a refractive index of about 2.65 against 2.42) and splits it into colour more than twice as much (dispersion of about 0.104 against 0.044). You see that as more brilliance and more rainbow-coloured fire.
Is moissanite durable enough to wear every day?
Yes. At 9.25 on the Mohs hardness scale, moissanite is harder than sapphire and ruby; only diamond, at 10, is harder. It is well suited to rings you wear every day.
Will moissanite go cloudy?
The stone itself does not cloud. Like any gemstone, it can look dull when lotion or skin oils build up on it, and a clean with warm water, mild soap and a soft brush brings the sparkle back.
Is moissanite ethically sourced?
Natural moissanite is extremely rare, so gem moissanite is created in laboratories rather than mined. That means no mining is involved in making the stone.
Why is moissanite less expensive than diamond?
Because it is grown in a lab instead of mined, moissanite costs a fraction of a diamond of similar size. You can choose a larger or more detailed piece for the same budget.
Want to learn more?
Our free guides to moissanite, diamonds, gold and precious gemstones live in the Karron Library, alongside more jewelry education as we add it.
Visit the Karron Library