Advice
Certification Guides
How GIA, IGI, AGS and other grading labs actually differ, and which to trust for what.
Grading Lab Comparison
| Lab | Best For | Strictness |
|---|---|---|
| GIA | Natural diamonds, especially 1ct+ | Strictest, most consistent |
| IGI | Lab-grown diamonds | Consistent, slightly generous |
| AGS | Cut-precision focus | Very strict on cut grade |
| EGL | Use with caution | Inconsistent across franchises |
Why the Lab Matters as Much as the Grade
A 'VS1' clarity grade from one lab is not always equivalent to the same grade from another — grading tolerance varies by lab, which is why two 'identical' certificates can describe visibly different stones.