Moissanite vs Lab Diamond: Differences, Price and Which to Buy

Moissanite vs lab diamond comes down to one fact: a lab diamond is a real diamond, and moissanite isn't. A lab diamond is pure carbon with the same crystal structure as a mined diamond, just grown in a lab. Moissanite is silicon carbide, a different gem that throws more colored sparkle, is slightly less hard and costs far less. Across three designs we sell in both stones, the lab diamond version costs 10 to 12 times as much.

We sell both. Here's how they compare, what "DEF moissanite" means, how to tell them apart and which to buy. Gem facts come from GIA, IGI and the FTC. Prices are ours, as of October 13, 2026.

Shop DEF MoissaniteShop Lab Diamonds

What are moissanite and lab diamonds?

Moissanite

Moissanite is silicon carbide (SiC). It's named after the French chemist Henri Moissan, who found tiny natural crystals of it in an Arizona meteorite in 1893. Natural moissanite only occurs as tiny grains, so every moissanite gem sold today, ours included, is grown in a lab. Gemologists class it as a diamond simulant: a different material that looks like diamond.

Lab diamonds

A lab diamond (also called lab-grown or lab-created) is carbon with the same crystal structure as a mined diamond. GIA, the Gemological Institute of America, says that gives it nearly the same chemical, optical and physical properties. As GIA explains, labs grow them in two ways:

• HPHT (high pressure, high temperature). A diamond seed sits in a press at 1,300 to 1,600°C and over 870,000 pounds per square inch. Carbon dissolves in molten metal and crystallizes onto the seed over days to weeks.
• CVD (chemical vapor deposition). Diamond seed plates sit in a vacuum chamber of hydrogen and a carbon gas such as methane at about 900 to 1,200°C. Microwaves turn the gas into plasma, and carbon builds up layer by layer over three or four weeks. Many CVD crystals are then heat-treated to remove a brownish tint.

Either way, the result is diamond. Our guide to what lab diamonds are has more.

Is a lab diamond a real diamond?

Yes. A lab-grown diamond is the same carbon crystal as a mined diamond and scores the same 10 on the Mohs scale. You can't tell the two apart with a jeweler's loupe; it takes lab testing. In 2018 the US Federal Trade Commission removed the word "natural" from its definition of a diamond. Sellers should still say clearly that a lab diamond isn't mined, with a term like "laboratory-grown" or "laboratory-created."

Is moissanite a lab-grown diamond?

No. Moissanite is grown in a lab too, but that doesn't make it a diamond. GIA lists moissanite with cubic zirconia and glass as diamond simulants, and the FTC's jewelry advertising guidance says simulants should be sold as not being diamonds. So "moissanite diamond" on a listing just means moissanite. Our guide to what moissanite is and isn't goes deeper.

Moissanite vs lab diamond: side-by-side comparison

A lab diamond's figures match a mined diamond's.

Key differences between moissanite and lab diamonds

Sparkle and fire

Fire, the rainbow flashes in a stone, comes from dispersion. Moissanite's is more than twice diamond's, so it throws noticeably more color, and its higher refractive index makes it look very bright. A lab diamond sparkles like a mined diamond: mostly white light with some color. Some people love moissanite's extra fire, and some find it too much in a big stone in direct sun. In the small stones on chains and bracelets, it mostly reads as extra brightness.

Hardness and durability

Diamond, mined or lab-grown, sits at 10, the top of the Mohs scale. Moissanite is 9.25, well above cubic zirconia at about 8 to 8.5. Both are fine for daily wear, but over decades a diamond resists scratches slightly better, which matters most on a ring.

Certification

Lab diamonds are graded by the same labs as mined ones. IGI, which has graded lab-grown diamonds since 2005, uses the usual D-to-Z color and IF-to-I3 clarity grades. Since October 1, 2025, GIA instead labels each lab-grown diamond "Premium" (D color, VVS2 clarity or better, and excellent polish, symmetry and, on rounds, cut) or "Standard," and laser-inscribes "Laboratory-Grown" on its edge. GIA's reason: most lab-grown diamonds fall into a very narrow range of color and clarity. Our moissanite comes with a GRA report listing its color, clarity and a number you can check.

Ethics and environment

Neither stone is mined, the main ethical draw of both. Neither is automatically green, though. IGI calls lab diamond production energy-intensive, and HPHT growth runs at 1,300°C and up for days or weeks. The FTC tells jewelers not to make broad "eco-friendly" claims they can't back up, so be wary of blanket green claims for either.

What does DEF moissanite mean?

"DEF" is a color grade. D, E and F are the top three letters on the D-to-Z scale GIA created for diamonds, and GIA calls that range colorless. Moissanite sellers use the same letters, so "DEF moissanite" means moissanite graded colorless. It isn't a separate kind of stone, and clarity (IF, VVS1, VVS2 and so on) is graded separately.

So in DEF vs GH moissanite, small stones look white to most people either way. It takes a trained eye, or a side-by-side with a D stone, to pick out the G or H. The first jewelry moissanite, in the late 1990s, was near-colorless at best; today's top grades are colorless. Lab diamonds use the same letters on IGI reports, and IGI says they frequently reach near-colorless to colorless grades, so DEF is common for them. Our moissanite is graded D with VVS1 clarity, across our DEF moissanite collection.

Price difference: moissanite vs lab diamond

Our own prices for the same designs in both stones, as of October 13, 2026:

Each pair has the same width and length. The metal differs: the moissanite versions list 18K white gold plating, and the lab diamond versions list 925 silver. In-stock moissanite ships from our US and UK warehouses. Lab diamond pieces are made to order and take about 4 weeks. Prices change, so check the product page. For chains, read lab diamond chains vs moissanite chains.

Resale value: moissanite vs lab diamond

Don't buy either one as an investment. IGI says buyers usually can't get back what they paid for any diamond, and that lab-grown diamonds are best seen as an up-front saving. New ones keep getting cheaper, too. Wholesale prices fell about 26% in 2025 and another 13 to 14% year over year in early 2026, according to analyst Edahn Golan's data, as reported by JCK. When new stones get cheaper every year, used ones are worth even less.

Moissanite isn't rare either, so a used piece sells for a fraction of its price. If neither holds its value, the cheaper stone is the smaller loss.

How to tell moissanite from a lab diamond

By eye, at normal distance, most people can't. These checks work:

1. Use a 10x loupe. Look into the stone at a slight angle. Moissanite is doubly refractive, so its back facet edges look doubled. A diamond's never do. GIA flagged this as the way to separate the two when moissanite first came out.
2. Use the right tester. A basic heat-based diamond tester reads moissanite as diamond, which the FTC warns jewelers about. A moissanite tester or multi-tester is built to flag it.
3. Watch it in sunlight. Stronger rainbow flashes point to moissanite.
4. Check the paperwork. A lab diamond should come with a lab-grown report from a lab such as IGI or GIA. A moissanite report, like GRA's, describes moissanite.

Telling a lab diamond from a mined one takes lab equipment, and IGI says jewelers' tools can only flag a suspected lab-grown stone. See how to tell if a diamond is lab-grown.

Pros and cons of moissanite and lab diamonds

Moissanite pros: a fraction of the price, more fire, tough enough for daily wear, never mined. Cons: not a diamond, can look too colorful in big stones, little resale value.

Lab diamond pros: a real diamond, top hardness, classic white sparkle, never mined. Cons: 10 to 12 times the price of the same piece in moissanite at our store, low and falling resale value, about 4 weeks to make.

Moissanite or lab diamond: which should you choose?

Choose moissanite if you want the biggest, brightest look for your budget, you're buying chains, bracelets or other pieces covered in small stones, or you like extra fire. For iced-out pieces, it's the stone we'd pick.

Choose a lab diamond if it matters to you that the stone is a diamond, you want the hardest stone for a ring you'll wear daily for decades, or you prefer diamond's whiter sparkle in a large center stone.

How to care for moissanite and lab diamonds

Both stones are tough, so care is mostly about the metal and the setting. Clean them with warm water, a drop of mild dish soap and a soft brush. Keep jewelry away from chlorine, bleach and abrasive cleaners, which can damage the finish. Our moissanite chain cleaning guide has the steps.

Our moissanite and lab diamonds

Our colorless moissanite is graded D color, VVS1 clarity. Every moissanite piece ships with a GRA report and passes a standard diamond tester. We sell it as moissanite, never as diamond.

We also make lab diamond pieces to order in many of the same designs, with lab diamonds listed as IGI-certified, VVS1 clarity. They take about 4 weeks and, because they're made for you, can't be cancelled or returned, so check your size first. Moissanite pieces are final sale too. Every piece comes with our lifetime warranty card, covering manufacturing defects, breakage in normal wear, fading of the finish and loose or lost stones.

Shop Moissanite Tennis ChainsShop Lab Diamonds

Moissanite vs lab diamond: common questions

Is moissanite a lab-grown diamond?
No. Moissanite is grown in a lab, but it's silicon carbide, not diamond. A lab-grown diamond is carbon, the same crystal as a mined diamond.

Is a lab diamond a real diamond?
Yes. It's the same carbon crystal as a mined diamond, with nearly the same chemical, optical and physical properties. Sellers should label it laboratory-grown or laboratory-created.

Which is better, moissanite or a lab diamond?
Moissanite gives you more fire and a bigger look for far less money. A lab diamond is a real diamond and slightly harder, at 10 to 12 times the price of the same piece in our store.

Which is cheaper, moissanite or a lab diamond?
Moissanite. As of October 13, 2026, our 3mm tennis chain in 20 inches costs $368.99 in D color VVS1 moissanite and $3,562.99 with IGI lab diamonds.

Do lab diamonds or moissanite have resale value?
Not much. Lab-grown diamond prices keep falling and moissanite isn't rare, so both resell for a fraction of what you paid. Buy either to wear, not to invest.

What does DEF moissanite mean?
Moissanite graded D, E or F, the colorless top of the D-to-Z color scale used for diamonds. It's a color grade, not a different stone.

Can you tell moissanite from a lab diamond?
Yes. Under a 10x loupe, moissanite shows doubled facet edges and a diamond doesn't. A moissanite tester also flags it, though a basic heat-based tester reads both as diamond.