Certification you can trust.
Every gemstone is individually documented, photographed, and sold as a singular piece.
Why certification matters
Certification is not a formality.
It is the foundation of trust.
Independent laboratory documentation
Vincentigue works with independent laboratories including Guild Laboratories, Lotus Gemology, GIA, AGA — American Gem Analysis Laboratory, GIT — The Gem and Jewelry Institute of Thailand and AGL Thai.
The issuing laboratory, report number and disclosed treatment information are presented for the individual stone.
Verify a report
Use the report number shown on the certificate to verify it directly with the issuing laboratory.
Guild Laboratories
GUILD traces its history to Los Angeles in 1980 and today operates laboratories in Hong Kong, Shenzhen and Bangkok. It is one of the most widely used laboratories in Asia, runs an active field gemmology programme in mining regions, and issues colour trade names – such as Kijani, Canary Yellow or Jedi – for stones that meet its defined colour criteria.
Guild is our primary laboratory partner for many coloured gemstones. Its reports document the stone’s identity, measurable characteristics and treatment findings, with origin opinions where applicable.
Lotus Gemology
An independent laboratory in Bangkok founded by Richard W. Hughes, Wimon Manorotkul and E. Billie Hughes. Lotus specialises in ruby, sapphire and spinel, and is highly regarded for its work on origin determination and treatment detection.
Its reports can include identity, treatment findings and origin opinions where applicable.
GIA
Founded in 1931, GIA is a non-profit institute that created the 4Cs and the International Diamond Grading System. Its reports are recognised by the trade worldwide and serve as a reference for diamonds and coloured gemstones alike.
Vincentigue uses GIA for selected diamonds and exceptional coloured stones. The specific report accompanying each piece is named on its product page.
AGA — American Gem Analysis Laboratory
An international coloured-gemstone laboratory with offices in Florida and Bangkok. AGA reports identify the species, confirm that the stone is natural and disclose detectable treatments, and come with high-definition photography of the stone.
AGA reports can be checked through the laboratory’s own verification service linked above.
GIT — The Gem and Jewelry Institute of Thailand
A public organisation under the Thai Ministry of Commerce, established by Royal Decree in 2003 with a mandate to test, classify and set standards for gems and jewellery. GIT reports carry a GIT number that can be checked through the institute’s own verification service.
AGL Thai
A Bangkok laboratory issuing identification reports for coloured gemstones, covering species, natural origin and treatment. Its reports can be checked online with the report number and the password printed on the report.
What certification does — and does not — do
A report documents: gemstone identity, treatment findings, measurable characteristics and, where stated, an origin opinion.
Origin and trade names are expert opinions based on each laboratory’s own reference data and criteria. We show them exactly as stated on the report, and never add a trade name the report does not carry.
A report does not determine beauty, desirability or future value on its own. Those qualities still require judgement and experience.
One stone. One report.
The laboratory report belongs to the exact stone shown and sold.
No shared reports. No substitutes.