The Trade,
Verified.

New York-based laboratory specialising in coloured gemstones, led by president and chief gemologist Christopher P. Smith - a 35+ year industry veteran, formerly of GIA and Gubelin, who relaunched AGL under his ownership in 2009. Known for origin determination and treatment disclosure on rubies, sapphires and emeralds.

Bangkok-based laboratory and gemmological school with nearly five decades of experience in coloured gemstone identification, origin and treatment reporting.

Independent laboratory with offices in Paris, Bangkok and Colombo, recognised for origin determination on ruby, sapphire and emerald - including reports on record-setting auction gemstones.

Independent Swiss laboratory founded by Edward Gubelin-trained gemmologist Christian Dunaigre, with offices in Switzerland and Bangkok. Respected for coloured gemstone identification, treatment disclosure and origin reports.

New York laboratory known for cut grading and consumer-protection reporting.

The global benchmark for diamond grading and coloured gemstone identification. Reports widely accepted across bridal and high jewellery.

Thailand's national gem laboratory and research centre, central to the Bangkok trade.

Influential in the Asian trade for ruby and sapphire reports, including Pigeon's Blood and Royal Blue colour calls.

Founded in New York in 2005, GSI is one of the world's largest gemmological laboratories by volume, with locations across four continents.

Lucerne laboratory with a century of coloured-gemstone research; pioneers of the Provenance Proof emerald paternity test.

Bangkok laboratory founded by Richard Hughes; regarded for ruby, sapphire and spinel expertise.

Basel-based laboratory respected at auction for origin reports on Kashmir sapphire, Burmese ruby and Colombian emerald.