A scientific reference for buyers, dealers, and collectors
The pages below summarise what AGL’s gemologists examine for each of the major gemstone families — origin signatures, treatment indicators, the analytical equipment used, and the grading framework applied. These are working reference articles, not marketing material: every detail reflects the protocols followed across our laboratories in Sri Lanka, Antwerp, and Shanghai.
For background on the analytical workflow common to every gem we certify, see our Process page. To verify a certificate already in your possession, use the verification portal.
