Moissanite vs Lab-Grown Diamond: How to Choose
Lab-grown diamond and moissanite are the two most popular alternatives to a mined diamond. Both are made in a lab, both are hard enough to wear every day, and both cost far less than a mined diamond of the same size. A lab-grown diamond is a real diamond. Moissanite is a different gemstone with a look of its own. Here is how they compare on sparkle, durability, price and value, and how to choose between them.
What each one is
A lab-grown diamond is carbon crystallized into diamond, grown either under high pressure and high temperature or by depositing carbon from a gas. The result has the same chemical, physical and optical properties as a mined diamond, and it is graded on the same scale of cut, color, clarity and carat, usually by the GIA or the IGI. Only specialist lab equipment can tell a lab-grown diamond from a mined one.
Moissanite is silicon carbide. It was first found in 1893 in a meteorite crater, and the moissanite used in jewelry today is created in a lab. It is its own gemstone, with properties that differ from diamond's.
| Moissanite | Lab-grown diamond | |
|---|---|---|
| Material | Silicon carbide | Carbon |
| Refractive index | 2.65 | 2.42 |
| Dispersion (fire) | 0.104 | 0.044 |
| Mohs hardness | 9.25 | 10 |
| Refraction | Double | Single |
How they look
Shown: Nora Oval Moissanite Solitaire Engagement Ring
A lab-grown diamond sparkles exactly like a mined diamond: mostly crisp white light, with flashes of color as it moves. Moissanite bends light more strongly and splits it into colors more than twice as much, so it throws more rainbow fire. The difference is easiest to see in sunlight and in stones of a carat or more.
Neither look is better. Some people love moissanite's extra color; others want the cooler, whiter sparkle of a diamond. If you can, look at both in daylight before you decide.
Durability
A diamond, lab-grown or mined, is the hardest gemstone at 10 on the Mohs scale. Moissanite is next at 9.25, harder than sapphire and ruby at 9. Both resist scratching and keep their polish through years of daily wear. Hardness is not the same as toughness, though: either stone can chip if it takes a hard knock on an edge or a point, so take your ring off for sports and heavy work.
Price
Lab-grown diamond prices have fallen for years as production has grown. The StoneAlgo price index, which tracks lab-grown diamonds listed by large online jewelers, shows prices down about 28 percent over the past year, as of October 2026. Even so, 2026 retailer price guides put a 1 carat lab-grown diamond solitaire in 14K gold at around $900 to $1,800.
Moissanite costs less again. Our moissanite engagement rings start at $88, set in 925 sterling silver with 18K gold plating, and most are under $200. For the same budget, moissanite buys a larger stone or a more detailed setting.
Resale value
Buy either stone to wear, not as an investment. Because lab-grown diamond prices keep falling, there is little resale market for them, and moissanite has no established resale market either. What you pay is the price of the ring you will wear, so choose the one you love at a price that feels comfortable.
Testing and grading
A lab-grown diamond reads as diamond on a thermal tester, because it is one. Some lab-grown diamonds contain traces of boron, which lets them conduct electricity, so a multi-tester can read them as moissanite. Larger stones usually come with a grading report from the GIA or the IGI, and many are laser-inscribed on the girdle as lab-grown, which settles the question.
Moissanite also reads as diamond on a basic thermal tester, because it conducts heat very well. A multi-tester that also measures electrical conductivity identifies it, and a jeweler can often spot it through a loupe by the doubled look of its back facets.
Which should you choose?
Shown: Marisa Oval Moissanite Side Stone Engagement Ring
- Choose a lab-grown diamond if a diamond specifically matters to you or the person you are proposing to, you prefer white sparkle to colored fire, and the budget allows for it.
- Choose moissanite if you want the most sparkle and the largest stone for your budget, in a stone hard enough for every day.
Whichever you choose, the setting matters as much as the stone. Our guide to engagement ring settings and guide to engagement ring shapes help with the rest.
Common questions
Is moissanite or lab-grown diamond better?
Neither is better for everyone. A lab-grown diamond is a diamond, with a diamond's white sparkle and hardness. Moissanite has more fire, nearly the same hardness and a much lower price.
Can people tell moissanite from a lab-grown diamond?
Most people cannot at a normal distance. Up close, moissanite's stronger rainbow fire can give it away, especially in larger stones. A jeweler can tell them apart with a multi-tester or a loupe.
Do lab-grown diamonds and moissanite last?
Yes. Both are hard enough to keep their polish for a lifetime of wear. The diamond is harder, at 10 against 9.25, and both can chip from a hard knock.
Do they hold their value?
Not well. Lab-grown diamond prices are still falling, and neither stone has much of a resale market. Choose the ring for how it looks and how it wears.
For moissanite against a mined diamond, read Moissanite vs Diamond, and against white sapphire, Moissanite vs White Sapphire. Browse our moissanite engagement rings or oval moissanite rings.
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