Moissanite vs Lab Grown Diamonds
Both are lab-created alternatives to mined diamonds, but they are fundamentally different gemstones with distinct properties.
Different Gemstones Entirely
Lab-grown diamonds are real diamonds—pure crystallized carbon with the same properties as mined diamonds. Moissanite is a completely different gemstone composed of silicon carbide (SiC). While both can be created in laboratories, they have different chemical compositions, optical properties, and characteristics.
Side by Side Analysis
| Property | Lab-Grown Diamond | Moissanite |
|---|---|---|
| Chemical Composition | Pure Carbon (C) | Silicon Carbide (SiC) |
| Hardness (Mohs) | 10 (Hardest natural substance) | 9.25 |
| Refractive Index | 2.42 | 2.65-2.69 (Higher) |
| Dispersion (Fire) | 0.044 | 0.104 (More rainbow fire) |
| Brilliance | Classic white brilliance | More colorful sparkle |
| Refraction Type | Single refractive | Double refractive |
| Origin | Lab-created or mined | Almost exclusively lab-created |
| Grading | 4Cs (Cut, Color, Clarity, Carat) | Primarily color graded |
| Is it a diamond? | Yes, real diamond | No, different gemstone |
Lab-Grown Diamonds
Lab-grown diamonds are chemically, physically, and optically identical to mined diamonds. They are pure carbon and score a 10 on the Mohs hardness scale—the hardest natural substance on Earth.
They produce classic diamond brilliance, reflecting white light in the characteristic way diamonds have been valued for centuries. Lab-grown diamonds are graded using the same 4Cs standards as mined diamonds.
Being real diamonds, they share all the properties that make diamonds the traditional choice for engagement rings and fine jewelry.
Moissanite
Moissanite is a gemstone composed of silicon carbide. Natural moissanite is extremely rare (found in meteorites), so virtually all moissanite in jewelry is lab-created.
With a higher refractive index and greater dispersion than diamond, moissanite produces more "rainbow fire"—the colored light flashes that appear when the stone is moved. This creates a more colorful sparkle that some find attractive, while others prefer diamond's classic brilliance.
Moissanite is double refractive, which can create a subtle doubling effect in larger stones, particularly under magnification.
Price Comparison (1 Carat Equivalent)
Understanding the price differences helps you find the right balance between budget and the qualities that matter most to you.
Moissanite
$300 - $600
Lowest entry point. Beautiful fire and brilliance. Ideal for fashion jewelry or budget-conscious buyers.
Lab-Grown Diamond
$800 - $2,000
Real diamond with full 4Cs grading. Maximum hardness and classic brilliance at a fraction of mined prices.
Mined Diamond
$3,000 - $8,000
Geological rarity and established resale market. Highest cost for identical optical properties.
Moissanite offers the lowest entry point, but lab-grown diamonds are real diamonds. For engagement rings, most buyers prefer diamond (lab or mined) for its hardness and prestige.
Which Should You Choose?
Choose Moissanite If...
- Budget is your top priority
- You love extra fire and rainbow flashes
- It's for fashion jewelry you'll rotate
Choose Lab-Grown Diamond If...
- You want a real diamond with full 4Cs grading
- Durability matters (10 vs 9.25 Mohs)
- Traditional engagement ring expectations matter to you
- You plan to insure the piece
For engagement rings: Most jewelers recommend diamonds (lab or mined) due to the hardness advantage and cultural significance. A lab-grown diamond gives you the best of both worlds — a real diamond at a more accessible price.
Daily Wear Durability
For jewelry worn every day — especially engagement and wedding rings — durability is a critical consideration. Here is how the two gemstones compare over years of wear.
10
Mohs Hardness
Lab-Grown Diamond
Scratch-resistant to everything except another diamond. The maximum possible hardness on the Mohs scale. Maintains its polish and brilliance indefinitely with normal wear. The gold standard for everyday jewelry durability.
9.25
Mohs Hardness
Moissanite
Very hard — harder than sapphire — but can develop surface scratches over years of daily wear. Both are suitable for everyday rings, though diamonds have the durability edge. In rare cases, moissanite can develop a slight surface haze over decades.
Both gemstones are suitable for daily wear. The 0.75-point difference on the Mohs scale may seem small, but the scale is non-linear — diamond is significantly harder than moissanite in absolute terms.
Frequently Asked Questions
No. Moissanite is a completely different gemstone — silicon carbide (SiC) — not a diamond imitation. It has its own unique optical properties, including higher fire (dispersion) than diamonds. It's a legitimate gemstone in its own right.
In most settings, they look similar to the untrained eye. However, moissanite has noticeably more "fire" — rainbow light dispersion — which some find beautiful and others find too flashy. A jeweler with a loupe can usually tell them apart by the double refraction in moissanite.
This is subjective. Moissanite has more colorful fire (rainbow flashes), while diamonds have more white light brilliance. In larger sizes (over 1 carat), moissanite's extra fire becomes more noticeable. Some love this; others prefer diamond's classic sparkle.
Yes, moissanite is suitable for engagement rings. At 9.25 on the Mohs scale, it's harder than sapphire and very durable. However, if traditional expectations or maximum durability matter, a lab-grown diamond may be the better choice.
Moissanite costs roughly 60-80% less than a lab-grown diamond. A 1-carat equivalent moissanite costs $300-$600, while a comparable lab-grown diamond costs $800-$2,000. The price gap narrows for premium-cut moissanite.
Neither is primarily an investment purchase. Lab-grown diamonds have emerging resale markets, while moissanite resale is minimal. Both are valued for their beauty and wearability rather than investment returns.
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Continue Learning: Lab Grown Diamonds · Lab vs Mined · The 4Cs · How They're Made