Yes. A laboratory-grown diamond is a real diamond. It is carbon crystallised in the same cubic structure as a natural diamond, with the same hardness, the same density and the same optical properties. The difference lies in where and how it formed.
Real, natural and imitation are different words
- Real describes what a material is. Diamond is diamond whether it grew in the earth or in a laboratory.
- Natural describes origin: formed by nature, without human intervention.
- Imitation (or simulant) describes a different material made to look like something else. Cubic zirconia imitates diamond; so, when sold as a diamond look-alike, can glass.
How regulators define diamond
The US Federal Trade Commission's Jewelry Guides define a diamond as a mineral consisting essentially of pure carbon crystallised in the isometric (cubic) system, with a hardness of 10, a specific gravity of approximately 3.52 and a refractive index of 2.42. In its 2018 revision, the Commission removed the word "natural" from that definition, recognising that diamonds can now be created with the same properties. The Guides still require laboratory-created diamonds to be clearly identified as such.
The physical evidence
| Property | Natural diamond | Laboratory-grown diamond | Cubic zirconia |
|---|---|---|---|
| Composition | Carbon | Carbon | Zirconium dioxide |
| Hardness (Mohs) | 10 | 10 | About 8–8.5 |
| Refractive index | About 2.42 | About 2.42 | About 2.15–2.18 |
| Specific gravity | About 3.52 | About 3.52 | About 5.6–6.0 |
So what should you ask?
Not "is it real?", but "is it natural or laboratory-grown?" and "is it described honestly?". A trustworthy description names the origin clearly and, for significant stones, is supported by an independent report. Read What does diamond certification mean?.
Why the confusion exists
For most of history, every diamond was natural, so "diamond" and "natural diamond" meant the same thing. When diamonds began to be grown in laboratories, the old words no longer drew the right lines. Advertising has added to the confusion: some sellers of natural stones describe them as the only "real" diamonds, while some sellers of laboratory-grown stones avoid naming their origin clearly. Neither practice helps the person choosing.
How to read a description
| Description | What it tells you |
|---|---|
| "Laboratory-grown diamond" or "laboratory-created diamond" | Clear and complete: diamond, grown by people |
| "Diamond" or "natural diamond" | A diamond formed in the earth |
| "Lab diamond" | Common shorthand; the full description should still state laboratory origin |
| "Diamond simulant", "imitation" | Not diamond: a different material that looks similar |
| "Cultured", "created", or no origin at all | Unclear on their own; ask for the full description in writing |
What "real" should mean when you buy
In practice, a trustworthy purchase means that the material is what it is said to be, that the origin is stated clearly, and that the grade is supported by an independent report for significant stones. Those three things matter far more than the word "real".
And moissanite?
Moissanite is a real gemstone, but it is not diamond. It is silicon carbide, with its own properties and its own name. Read Moissanite vs lab-grown diamond.
Sources: US Federal Trade Commission, Guides for the Jewelry, Precious Metals, and Pewter Industries, 16 CFR Part 23 (revised 2018); Gemological Institute of America (gia.edu), resources on laboratory-grown diamonds.
Frequently asked questions
Is a lab-grown diamond fake?
No. It is diamond. A fake, or imitation, is a different material made to look like diamond.
Why do some people say lab-grown diamonds are not real?
Usually they mean not natural. Origin is a legitimate reason to prefer one or the other, but it does not change the material.
Is a lab-grown diamond a simulant?
No. A simulant is a different material that imitates diamond; a laboratory-grown diamond is diamond.
Does a lab-grown diamond test as diamond?
Yes. Standard testers identify it as diamond because it is. Only laboratory analysis reveals whether it grew in the earth or in a laboratory.
