Lab-grown vs natural diamond
Both are diamond: same carbon, same hardness, same optical properties. That is precisely why telling them apart is a laboratory job.
Updated 2026-10-24
Why the difference is invisible
A lab-grown diamond has the same composition (carbon), the same cubic structure, the same refractive index (2.417), the same dispersion (0.044), the same Mohs hardness (10) and the same specific gravity (3.52) as a natural diamond. Instruments that identify diamond identify both. Nothing in a photograph could possibly distinguish them, because there is no physical difference to see.
What differs is growth history: trace elements, strain patterns, and in many cases a laser inscription on the girdle. Those are read with spectroscopic and microscopic methods — UV fluorescence imaging, FTIR, Raman, and photoluminescence — by laboratories set up for it.
The one thing a photo can carry
An inscription. Many lab-grown stones are laser-inscribed on the girdle with the laboratory name and report number, and the wording is explicit. If you can photograph that inscription legibly, you have real information — but only about that report, not about the stone's quality or value.
The reverse caution matters more: the absence of a visible inscription proves nothing. Inscriptions can be polished away, and plenty of natural stones carry none.
Why the distinction is a pricing and disclosure question
The two markets are separate, and prices differ substantially, so the consumer risk is being sold one as the other. That makes disclosure the real issue, and reliable disclosures come with a report. A seller's assurance, a screen result or a photo are not substitutes.
Common questions
Can a jeweller tell lab-grown from natural by eye?
No. Trained gemmologists may notice growth-related strain or inclusion patterns under a microscope that prompt further testing, but a definitive call needs laboratory instruments.
Are lab-grown diamonds inferior?
They are chemically and optically identical to natural diamond. The difference is origin, and therefore price and resale behaviour — not durability or appearance.
Is an inscription enough to confirm origin?
A legible laboratory inscription is evidence that a stone was submitted for a report. It is not a guarantee about the stone in front of you, and it can be removed.
Screen a stone from a photo
Preliminary AI-assisted screening: likely species, cut and colour, plus the reference values for that species. Not a certification, and not a replacement for a laboratory report.
Related guides
Educational content only. Gemmological values quoted here are published reference data for the species named, not measurements of any particular stone. Gemology Lens provides preliminary AI-assisted screening and does not authenticate, grade or value gemstones.