Lab Grown Diamond vs Moissanite
Updated 10 August 2026 · 4 min read
A lab grown diamond is a real diamond grown in a lab — identical to a mined diamond in every way except origin. Moissanite is a separate gemstone (silicon carbide) that looks similar, is slightly softer, has more fire, and costs significantly less. Both are ethical and conflict-free.
What they are
A lab grown diamond is chemically, physically and optically identical to a mined diamond — it is carbon in the same crystal structure, grown in a controlled environment over weeks rather than formed underground over millions of years. Independent labs such as IGI grade lab grown diamonds on the same 4Cs scale used for mined diamonds.
Moissanite is a different material entirely: silicon carbide, originally discovered in a meteorite and now created in a lab. It is not a diamond and is not sold as one — it is a distinct gemstone chosen for its brilliance, durability and value.
Hardness and durability
Diamond is the hardest known material at 10 on the Mohs scale, so a lab grown diamond is the most scratch-resistant option and the best choice if you want the toughest possible everyday stone.
Moissanite is 9.25 on the Mohs scale — just below diamond and harder than sapphire or ruby. In practice, that makes it a genuinely durable everyday stone; the difference matters more on paper than in daily wear.
Look: brilliance and fire
Lab grown diamonds have the classic diamond balance of white brilliance and subtle fire that most people picture when they think of a diamond.
Moissanite has more fire — it throws noticeably more colourful, rainbow flashes, especially in larger sizes and bright light. Whether that is a plus or a minus is personal preference: some love the extra sparkle, others prefer the more restrained look of a diamond.
Price
Moissanite costs a fraction of a lab grown diamond of the same size, and both cost far less than a mined diamond. That price gap is the deciding factor for many people: with moissanite, the budget stretches further on carat weight, metal or setting; with a lab grown diamond, you get an actual diamond for much less than a mined equivalent.
Ethics
Both are ethical, conflict-free choices. Neither involves diamond mining, and both are created in controlled environments. If avoiding the environmental and social impact of mining is a priority, either option delivers that.
| Lab Grown Diamond | Moissanite | |
|---|---|---|
| Material | Carbon (real diamond) | Silicon carbide |
| Hardness (Mohs) | 10 (hardest) | 9.25 (very durable) |
| Look | Classic diamond brilliance | More fire / rainbow sparkle |
| Price | Lower than mined diamond | Lowest of the three |
| Certification | IGI graded (4Cs) | GRA graded |
| Ethics | Conflict-free, no mining | Conflict-free, no mining |
Frequently Asked Questions
Is a lab grown diamond a real diamond?
Yes. A lab grown diamond has the same chemistry, hardness and optical properties as a mined diamond — the only difference is that it was grown in a lab rather than formed underground.
Can people tell the difference between them?
To the naked eye they look similar, though moissanite shows more colourful fire. A jeweller with the right tools can distinguish them, but both look beautiful set in a ring.
Which is better for an engagement ring?
Both are excellent. Choose a lab grown diamond if you want an actual diamond at a lower price; choose moissanite for maximum sparkle and value so more budget goes to the setting or carat weight.
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