International Gemological Institute
The trade uses IGI for grading reports on natural and laboratory-grown diamonds, coloured stones and finished jewellery, and for its gemmology schools.
The record
What it covers
Reports it publishes
Named as the laboratory names them on its own site. Report contents and wording are set by the laboratory, not by us.
- Natural Diamond Report
- Colored Stone Report
- Jewelry Report
Worth knowing
IGI lists four global head offices, in Antwerp, New York, Mumbai and Shanghai, and does not designate one as a single headquarters. Country of origin appears on the Colored Stone Report only where analysis conclusively reveals it. IGI announced on 31 January 2026 that it had acquired American Gemological Laboratories.
Compiled from igi.org, read on August 16, 2026.
We verify dealers, not stones. A laboratory report describes one stone on one date; it is not a guarantee of value, and it is not ours to stand behind.