- Jewelry Identifier
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- Lab-grown diamond
* diamond gemstone
Lab-grown diamond: identification, value, and how to spot a fake
Synthetic diamond grown by HPHT (high-pressure high-temperature) or CVD (chemical vapor deposition). Physically and chemically identical to natural diamond. Distinguishable only by spectroscopic testing (presence of CVD growth striae, HPHT cuboctahedral growth pattern). Per FTC, must be disclosed as 'lab-grown', 'synthetic', or 'man-made'.
Published May 30, 2026
Quick facts
- Mineral family
- diamond
- Chemical formula
- C
- Mohs hardness
- 10
- Refractive index
- 2.417–2.419
- Specific gravity
- 3.5–3.53
- Crystal system
- cubic
- Luster
- adamantine
- Dispersion
- 0.044
- Birthstone month
- April
Colors
Lab-grown diamond is found in colorless, yellow, pink, blue. The body color, its saturation, and how evenly it spreads through the stone are among the strongest drivers of value.
How to tell real from imitation
No single test settles it, but a few grounded checks quickly narrow things down for Lab-grown diamond. Hardness, brilliance, and the list of stones it is commonly confused with all give you something concrete to look for.
- Scratch resistance: genuine Lab-grown diamond sits at Mohs 10, so it should resist scratching from softer materials — a stone that mars far too easily is suspect.
- Brilliance & luster: Lab-grown diamond shows a adamantine luster and a refractive index of 2.417–2.419; imitations often look glassier or flatter under the same light.
- Density: a real Lab-grown diamond has a specific gravity near 3.5–3.53, so it feels heavier or lighter in the hand than many look-alikes of the same size.
- Commonly imitated by: moissanite, cubic zirconia. If a deal looks too good, suspect one of these substitutes first.
- Fast first read: photograph the stone in the Jewelry Identifier app to estimate the gemstone and its likely value range, then confirm anything important with a gemological lab.
Common treatments
- HPHT post-treatment
- irradiation
Treatments are routine for many Lab-grown diamond stones, but they materially affect value and should always be disclosed — an untreated, lab-certified stone commands a clear premium over a treated one.
What to know about Lab-grown diamond
Synthetic diamond grown by HPHT (high-pressure high-temperature) or CVD (chemical vapor deposition). Physically and chemically identical to natural diamond. Distinguishable only by spectroscopic testing (presence of CVD growth striae, HPHT cuboctahedral growth pattern). Per FTC, must be disclosed as 'lab-grown', 'synthetic', or 'man-made'.
Sources
* Frequently asked
FAQ
- Q. Is Lab-grown diamond hard enough for everyday rings?
- A. Yes. At a Mohs hardness of 10, Lab-grown diamond is durable enough for daily-wear rings; it resists the scratches that everyday surfaces inflict.
- Q. How can I tell Lab-grown diamond from moissanite?
- A. Lab-grown diamond and moissanite can look alike to the naked eye, but they differ in measurable properties — refractive index (2.417–2.419 for Lab-grown diamond), specific gravity (3.5–3.53), and hardness (Mohs 10). A gemologist confirms the distinction with a refractometer and loupe; the Jewelry Identifier app gives a fast first read from a photo.
- Q. Does Lab-grown diamond come in colors other than colorless?
- A. Yes. Lab-grown diamond occurs in colorless, yellow, pink, blue. Color is driven by trace elements and treatment history, and it is one of the biggest factors in a stone's value.
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