GIA to Introduce Premium & Standard Grading for Lab-Grown Diamonds Starting October
From October 1, the Gemological Institute of America (GIA) will discontinue traditional 4Cs grading for lab-grown diamonds and shift to a two-tier system: “Premium” and “Standard.”
Starting October 1, 2025, the Gemological Institute of America (GIA) will phase out its traditional 4Cs grading reports for lab-grown diamonds and implement a streamlined two-tier classification system. Diamonds will now be evaluated as either “Premium” or “Standard,” according to specific quality benchmarks.
The new system, initially announced in June without a firm launch date, was officially detailed by GIA in a statement released on August 26. Diamonds that do not meet the minimum standards for the “Standard” tier will not receive a grading report but will still be subject to evaluation fees.
Grading Criteria:
Premium Lab-Grown Diamonds:
- Clarity: VVS (Very, Very Slightly Included) or better
- Color: D
- Polish & Symmetry: Excellent
- Cut: Excellent (round brilliant only)
Standard Lab-Grown Diamonds:
- Clarity: VS (Very Slightly Included)
- Color: E to J
- Polish: Very Good
- Symmetry: Very Good (or Good for fancy shapes)
- Cut: Very Good (round brilliant only)
Diamonds falling below the “Standard” category will not be graded but will still incur an evaluation fee of $15 per carat, with a minimum fee of $15.
“Using descriptive terms for the quality of laboratory-grown diamonds is appropriate as most fall into a very narrow range of color and clarity,” said Pritesh Patel, President and CEO of GIA. “Because of that, GIA will no longer use the nomenclature created for natural diamonds to describe what is a manufactured product.”
The decision signals a significant shift in how lab-grown diamonds will be assessed and marketed. While GIA is moving away from the 4Cs for synthetics, IGI (International Gemological Institute), a major competitor, has confirmed it will continue using the traditional 4Cs grading for lab-grown stones — emphasising the need for grading consistency to avoid confusing both retailers and consumers.
This divergence in approach reflects the evolving landscape of the diamond industry as it adapts to the growing popularity of lab-grown alternatives.
