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Diamond Grade Standard
Natural Diamond vs Lab-Grown Diamond Grading Standards
GIA grading comparison
How GIA grades each kind of diamond
| Comparison | Natural Diamond (GIA 4Cs) | Lab-Grown Diamond (GIA Quality Assessment) |
|---|---|---|
| Grading System | 4Cs: Color, Clarity, Cut, Carat Weight | Descriptive terms: Premium or Standard |
| Color | D (colorless) to Z (light yellow/brown), 23 grades | Premium: D Standard: E–J |
| Clarity | FL (flawless) to I3 (included), 11 grades | Premium: VVS and above Standard: VS and above |
| Cut | Excellent to Poor, 5 grades | Premium: Excellent Standard: Very Good (round) |
| Grading Logic | Each diamond receives a specific grade based on its own parameters | Must meet all Premium criteria to be graded Premium; if any single criterion drops to Standard, the overall grade becomes Standard |
Key difference
Why the systems look different
Natural diamond 4C grading reflects the wide range of quality variations formed in nature; lab-grown diamonds, due to industrial mass production, over 95% fall within an extremely narrow color and clarity range, so GIA uses a simplified two-tier description instead.
Quick selection guide — Natural Diamond: check the specific 4C grades on the GIA certificate — grade differences directly affect value.
Quick selection guide — They’re Lab-Grown diamonds with an IGI certificate: just look for “Premium” or “Standard” — the core advantage is cost-effectiveness, no need to obsess over specific parameters.
Not sure which to choose for your custom piece? Make an appointment and we will help you select the diamond that fits your design and budget.