Are Lab-Grown Diamonds Real Diamonds?
Yes. Lab-grown diamonds are real diamonds in every measurable sense. They have the same chemical composition (pure crystalline carbon), the same crystal structure (face-centred cubic), the same hardness (10 on the Mohs scale), and the same optical properties as natural diamonds. The FTC, GIA, ISO, and CIBJO all confirm this. A lab-grown diamond is not a simulant, not an imitation, and not "fake."
What Makes a Diamond a Diamond
A diamond is defined by its atomic structure: carbon atoms bonded through sp3 hybridisation in a face-centred cubic lattice. This structure produces a refractive index of 2.417, a dispersion of 0.044, and the adamantine lustre that gives diamonds their distinctive appearance.
These properties are a consequence of the crystal structure — not of where or how that structure formed. Whether carbon crystallised 150 kilometres below the Earth's surface over a billion years or grew in a laboratory chamber over a few weeks, the resulting material is diamond. No gemological test based on physical properties can distinguish between the two.
The FTC Confirmed It
In 2018, the US Federal Trade Commission updated its Jewelry Guides to remove the word "natural" from its baseline definition of diamond. The revised definition describes diamond by its measurable properties — hardness, refractive index, specific gravity — without restricting the definition to geological origin.
This change explicitly acknowledged that lab-grown diamonds are real diamonds. At the same time, the FTC maintained that lab-grown diamonds must be disclosed as such at the point of sale. The unqualified word "diamond" in commerce still refers to the natural mineral, and lab-grown stones must carry a qualifier like "laboratory-grown" or "laboratory-created."
The distinction is about origin and transparency, not about whether the stone is genuine.
Diamonds vs Simulants
Lab-grown diamonds should not be confused with diamond simulants — materials that look like diamond but have different chemical and physical properties:
| Material | Composition | Hardness (Mohs) | Refractive Index |
|---|---|---|---|
| Diamond (natural or lab-grown) | Carbon (C) | 10 | 2.417 |
| Moissanite | Silicon carbide (SiC) | 9.25 | 2.65–2.69 |
| Cubic zirconia | Zirconium dioxide (ZrO₂) | 8–8.5 | 2.15–2.18 |
| White sapphire | Aluminium oxide (Al₂O₃) | 9 | 1.76–1.77 |
Moissanite, cubic zirconia, and white sapphire are entirely different materials. They have different chemical compositions, different crystal structures, and different optical behaviour. A trained eye can often distinguish them from diamond, and basic gemological instruments confirm the difference quickly.
A lab-grown diamond, by contrast, is the same material as a natural diamond. It passes every gemological test for diamond because it is diamond.
How They Are Made
Two methods produce virtually all gem-quality lab-grown diamonds:
HPHT (High Pressure, High Temperature) recreates the extreme conditions of the Earth's mantle in a laboratory press — pressures of 5–6 GPa and temperatures of 1,300–1,600 °C. A small diamond seed crystal is placed in a carbon source, and under these conditions, carbon atoms crystallise onto the seed, growing a larger diamond over days to weeks.
CVD (Chemical Vapour Deposition) takes a different approach. A diamond seed is placed in a vacuum chamber filled with carbon-rich gas (typically methane). The gas is ionised into plasma, and carbon atoms deposit onto the seed layer by layer, building the diamond at lower pressure than HPHT.
Both methods produce genuine diamond — the same carbon lattice, the same physical constants, the same brilliance, fire, and scintillation when properly cut.
What Is Different
If lab-grown diamonds are real diamonds, what distinguishes them from natural diamonds? Three things:
Origin. Natural diamonds formed through geological processes over billions of years. Lab-grown diamonds are manufactured in weeks. This is a factual distinction, not a quality judgement.
Rarity. Natural diamond supply is geologically finite. Lab-grown supply can be scaled by adding manufacturing capacity. This difference in supply dynamics is the primary driver of the price gap between the two categories.
Value trajectory. Natural diamonds hold value more consistently over time, supported by scarcity and established secondary markets. Lab-grown diamond prices have declined roughly 70% since 2022, with minimal resale value, as production scales and technology improves.
The GIA Grades Both
The GIA — the world's most widely recognised grading laboratory — issues grading reports for both natural and lab-grown diamonds. Lab-grown diamonds receive a dedicated Laboratory-Grown Diamond Report with full 4Cs grading (Cut, Colour, Clarity, Carat Weight), plus identification of the growth method (CVD or HPHT) and any post-growth treatments.
Every lab-grown diamond graded by the GIA is laser-inscribed on the girdle with "Laboratory-Grown" and the report number — a permanent, microscopic marker that travels with the stone.
The Bottom Line
A lab-grown diamond is a real diamond. It will test as diamond on any gemological instrument, it will look like diamond to every observer, and it will perform like diamond on your hand. The question is not whether it is genuine — it is. The question is whether the origin, rarity, and value characteristics of a natural diamond matter to you. For many buyers, the geological story, the finite supply, and the enduring value of a natural diamond carry meaning that goes beyond the physical stone.
Learn More
- Natural vs Lab-Grown Definitions — how the FTC, GIA, and trade bodies define each category
- Diamond vs Simulants — how diamond differs from moissanite, cubic zirconia, and other look-alikes
- Lab-Grown Overview — HPHT, CVD, and the technology behind laboratory diamonds