Both are diamond. The real difference is origin, one grown in a controlled setting and one formed in the earth. An independent lab report should state that origin clearly.
Are lab-grown diamonds real diamonds?
Yes. A lab-grown diamond is carbon arranged in the same crystal structure as a mined diamond, with essentially the same chemical, optical and physical properties. It's 10 on the Mohs hardness scale, it takes the same cut and polish, and it throws the same kind of light.
They're not simulants. Cubic zirconia and moissanite look like diamonds but are different materials with different hardness and different optics. A lab-grown diamond is diamond.
Side-by-side comparison
| Lab-grown diamond | Natural diamond | |
|---|---|---|
| Material | Crystallized carbon | Crystallized carbon |
| Hardness | 10 (Mohs) | 10 (Mohs) |
| Graded on the 4Cs | Yes | Yes |
| Origin | Grown above ground in weeks | Formed underground over millions to billions of years |
| Visible difference | None to the naked eye | None to the naked eye |
| How origin is confirmed | Lab testing and report | Lab testing and report |
| Typical price for the same specs | Much lower | Much higher |
| Resale value | Very limited | Limited, but higher than lab-grown |
How lab-grown diamonds are made: CVD and HPHT
There are two main methods.
HPHT (high pressure, high temperature) recreates the conditions deep in the earth. A small diamond seed sits in a press with carbon, and extreme heat and pressure grow new diamond around it.
CVD (chemical vapor deposition) grows diamond in a vacuum chamber. A carbon-rich gas is heated until carbon atoms settle onto a diamond seed plate, layer by layer.
Neither method makes a "better" diamond by default. Each can produce excellent stones and each has its own growth patterns that labs use to identify it. Some CVD diamonds are treated after growth to improve color, and a lab report should say so if treatment is detected. IGI reports note the growth method and any post-growth treatment found.
Can anyone tell them apart?
Not by looking. A jeweler holding a lab-grown diamond and a natural one of the same grades can't reliably tell which is which, even with a loupe.
Standard diamond testers, the handheld thermal and electrical kind, will read both as diamond. Telling origin apart takes specialized lab equipment that looks at growth structure, fluorescence patterns and trace elements. That's why the lab report matters so much. It's the document that states where the stone came from.
Many lab-grown diamonds also carry a laser inscription on the girdle with the report number, which ties the stone to its paperwork.
Price and resale
This is where the two really split.
Lab-grown diamonds cost far less than natural diamonds of the same size and grades. Prices have also dropped steadily over the past several years as production has grown. That's good news for buyers and a reason to be careful with anyone pitching lab-grown diamonds as an investment.
Resale value on lab-grown diamonds is very limited. Natural diamonds don't resell for anywhere near retail either, but they do hold more. If resale matters to you, that's a real point in favor of natural. If what matters is the size and look you get for your budget, lab-grown gives you far more stone for the money.
The honest way to think about it: buy a lab-grown diamond because you want to wear it, not because you expect to sell it later.
How lab-grown diamonds must be labeled
In the US, the Federal Trade Commission's Jewelry Guides require that a lab-grown diamond be clearly described as such. Sellers can use terms like "laboratory-grown," "laboratory-created" or "[manufacturer]-created." What they can't do is call it simply a "diamond" without that qualifier, or use terms that imply it came out of the ground.
Any legitimate seller will state origin plainly on the listing and the report. If a listing is vague about where a stone came from, ask before you buy.
The plain-language checklist
- Confirm "laboratory-grown" or "natural" on the report itself, not just the listing.
- Read the 4Cs and measurements for the exact stone.
- Check whether any post-growth treatment is disclosed.
- Match the report number to the stone.
- Keep appraisals, insurance values and resale talk separate from the grading report.
- Treat environmental and savings claims as claims. Ask for specifics.