Lab-grown and natural diamonds are graded on the same color and clarity scales. But there are practical differences in how the grades distribute, what types of inclusions you will see, and which grading labs certify each type. Here is what matters when you are choosing.
Same Scales, Different Distribution
Both types use the GIA D–Z color scale and FL–I3 clarity scale. But the distribution of grades is very different:
| Aspect |
Natural Diamond |
Lab-Grown Diamond |
| Color range |
Full D–Z spectrum. Most gem-quality naturals are G–J. |
Majority are D–G. Growing conditions can be controlled to minimize color. |
| Clarity range |
Full FL–I3 spectrum. Most are VS2–SI2. |
Most are VS1–VVS2. Fewer severe inclusions due to controlled growth. |
| Inclusion types |
Natural: feathers, crystals, pinpoints, clouds, needles, twinning wisps |
HPHT: metallic flux inclusions. CVD: strain lines, small pinpoints. |
| Primary grading lab |
GIA (gold standard for naturals) |
IGI (most widely used for lab-grown) |
| Grading consistency |
GIA is the strictest, most conservative grader |
IGI may grade 0.5–1 grade more generously on color/clarity than GIA would |
GIA vs. IGI Grading for Lab Diamonds
Most lab-grown diamonds are certified by IGI. Some are certified by GIA. Here is how to think about the difference:
- IGI-graded lab diamonds: The industry standard for lab-grown. Reliable and consistent. Some gemologists note that IGI grades may be slightly more generous than GIA — meaning an IGI G-color might be graded H by GIA. This is a minor difference and does not affect beauty.
- GIA-graded lab diamonds: Stricter grading. A GIA G-color lab diamond is graded to the same standard as a GIA G-color natural diamond. GIA lab reports are available but less common in the market.
Practical takeaway: When comparing a natural diamond (GIA) to a lab diamond (IGI), consider that the lab diamond's grades may be slightly optimistic. An IGI F-color lab diamond might be comparable to a GIA G-color natural. This is a minor nuance — both will look beautiful. For a deep dive, see our
Diamond Certification Guide.
HPHT vs. CVD Lab Diamonds
Lab diamonds are grown using two methods, each producing different types of inclusions:
| Method |
Process |
Typical Inclusions |
Color Notes |
| HPHT |
High Pressure, High Temperature — mimics natural diamond formation |
Metallic flux inclusions (tiny metal particles). Can appear as dark spots under magnification. |
Can produce very white stones (D–E). Some may have slight blue tint. |
| CVD |
Chemical Vapor Deposition — grows diamond layer by layer from gas |
Strain lines, small pinpoints. Generally cleaner than HPHT at equivalent grades. |
May have slight brown tint before post-growth treatment. Treated stones are typically D–G. |
For practical purposes, HPHT and CVD lab diamonds look identical once mounted. The growth method is noted on the grading report but does not affect the beauty of the finished diamond in any visible way.
Recommended Grades: Lab vs. Natural
|
Natural (GIA cert) |
Lab-Grown (IGI cert) |
| Best value color |
G–H |
F–G (since they're cheaper, you can afford higher grades) |
| Best value clarity |
VS2–SI1 |
VS1–VS2 (same logic — higher grades are affordable) |
| Sweet spot |
G / VS2 |
F / VS1 |
Because lab diamonds cost so much less, you can afford to be pickier about color and clarity. Where a natural diamond buyer might choose G/SI1 to stay on budget, a lab diamond buyer at the same budget can get F/VS1 — a visible upgrade in clarity and a slight improvement in color.