Are lab-grown diamonds GIA certified?

Premium means the stone hits the top of every factor at once: D colour, VVS or better clarity, excellent polish and symmetry, and an excellent cut grade on round brilliants. Standard covers E to J colour with VS clarity and very good finish grades. Anything below that threshold is returned with no grade for a small evaluation fee. Every graded stone is laser-inscribed "Laboratory-Grown" on the girdle with a unique GIA number.

Reports issued before October 2025 keep their original colour and clarity letters, so a "GIA certified lab-grown diamond" with a full 4Cs report is simply one graded under the old system. The stone has not been re-classified.

IGI is the dominant grading lab for lab-grown diamonds worldwide and still issues full 4Cs reports on them: specific colour, clarity, polish, symmetry and cut grades, plus a laser inscription you can verify on IGI's website in under a minute. GCAL and HRD Antwerp do the same. Because GIA's detailed reports often cost more than small lab-grown stones are worth, the market settled on IGI long before GIA simplified its system.

For buyers the practical takeaway is that an IGI report is the normal, trusted paperwork for a lab-grown diamond, not a step down. Whichever lab grades the stone, match the inscription on the girdle to the report number and verify it online before you buy.