A grading report is the closest thing a diamond has to a passport. Here's who issues them, what changed in 2025, and how to check one.
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Two labs, briefly
| GIA | IGI | |
|---|---|---|
| Full name | Gemological Institute of America | International Gemological Institute |
| Founded | 1931; a public-benefit nonprofit | 1975 in Antwerp, Belgium |
| Known for | Created the 4Cs and, in 1953, its International Diamond Grading System | Says it began certifying lab-grown diamonds in 2005; reports about 65% of global lab-grown certifications (CY 2023, its own figure) |
Sources: GIA and IGI's own pages and IGI's annual report.[1][2][3][4]
The big change: how GIA now reports lab-grown diamonds
Since 1 October 2025, GIA no longer gives lab-grown diamonds the color and clarity grades it uses for natural diamonds. It describes them as "Premium" or "Standard" in a Laboratory-Grown Diamond Quality Assessment:[5]
- Premium: D color, VVS clarity or higher, Excellent polish and symmetry, and Excellent cut for round brilliants.
- Standard: at least VS clarity, E-to-J color, Very Good polish and symmetry (Good symmetry for fancy shapes), and Very Good cut for round brilliants.
- Stones below Standard receive no GIA assessment. Each assessed stone is laser-inscribed with "Laboratory-Grown" and its assessment number.
The reason: lab-grown diamonds now cluster at the top of the scales. National Jeweler reported that since 2022, 95% of the lab-grown diamonds submitted to GIA were D to F color and 98% were VS1 or higher.[8] GIA's fee is $15 per carat (minimum $15), for stones of 0.15 ct and up.[5]
How IGI reports lab-grown diamonds
IGI's Laboratory Grown Diamond Report still uses the familiar scales: color from D to Z and clarity from IF to I, plus a cut grade for round brilliants and polish and symmetry for all shapes. On request, it notes the growth process and any treatments.[3]
So which is better?
For a lab-grown diamond, an IGI report gives you more detailed color and clarity grades. A GIA assessment tells you whether the stone clears its Premium or Standard bar. Neither replaces looking at the stone, its proportions and the retailer's return policy.
Check the report before you pay
- Match the report number on the paperwork to the laser inscription on the stone's girdle, and to the lab's online record. GIA offers Report Check on its website.[6]
- Confirm the report says "laboratory-grown" for a lab-grown stone.
- Be alert to fraud: in January 2024 GIA warned of lab-grown or treated diamonds bearing counterfeit GIA inscriptions copied from natural-diamond reports, and launched a same-day inscription verification service.[7]
- Moissanite is often sold with a GRA card. That isn't an IGI or GIA diamond report (see moissanite vs lab-grown).
Sources
- GIA, The GIA Difference. https://www.gia.edu/gia-about
- IGI, 28th Annual Report (2026). https://investor.igi.org/wp-content/uploads/2026/07/28th-Annual-Report-IGI.pdf
- IGI, Laboratory Grown Diamond Report. https://www.igi.org/reports/lab-grown-diamond-report/
- IGI, About. https://www.igi.org/about/
- GIA, GIA Launches Updated Laboratory-Grown Diamond Services October 1 (26 Aug 2025). https://www.gia.edu/gia-news-press/updated-laboratory-grown-diamond-services-to-launch-october-1
- GIA, Report Check. https://www.gia.edu/report-check-landing
- GIA, GIA to Offer Same-Day Report Verification (9 Jan 2024). https://www.gia.edu/gia-news-press/same-day-report-verification
- National Jeweler, GIA Reverting to More General Terminology for Lab-Grown Diamonds. https://nationaljeweler.com/articles/13980-gia-reverting-to-more-general-terminology-for-lab-grown-diamonds
Sources opened on or before 12 November 2026.