Asian Institute of Gemological Sciences (AIGS)
Level B1 (Unit B24), Jewelry Trade Center, 919/1 Silom Road, Bangkok 10500
Bangkok, Thailand
Specialty: Coloured stones; treatments and origin
Gem laboratories
Laboratories that test and grade diamonds, coloured stones and pearls, and assay offices that test precious metals, around the world.
Asia
Central Gem Laboratory (CGL)
Tokyo, Japan
Specialty: Diamonds, coloured stones, pearls
Far East Gem Lab
Singapore, Singapore
Specialty: Diamonds, gemstones, jade; jewellery appraisal
GAAJ-ZENHOKYO Laboratory
Tokyo, Japan · also Osaka, Kobe
Specialty: Diamonds, coloured stones, pearls; origin reports
Website not available
GIA Laboratory Bangkok (Gemological Research (Thailand))
Mitrtown Office Tower, 19th floor, 944 Rama IV Road, Wang Mai, Pathum Wan, Bangkok 10330
Bangkok, Thailand
Specialty: Diamonds, coloured stones and origin, pearls
GRS (Thailand)
228-230 Mahesak Road, Suriyawongse, Bangrak, Bangkok 10500
Bangkok, Thailand
Specialty: Coloured stones; treatment and origin
GUILD Gem Laboratories
Hong Kong, Hong Kong SAR · also Bangkok
Specialty: Coloured stones, pearls
Gem and Jewelry Institute of Thailand (GIT)
ITF Tower, 4th floor, 140 Silom Road, Suriyawong, Bangrak, Bangkok 10500
Bangkok, Thailand
Specialty: Gemstones, diamonds, precious metals (national institute)
Gemmological Institute of India (GII)
Mumbai, India
Specialty: Gemstones, diamonds; treatment detection
Gemological International Laboratories (GIL)
Room 302, 3rd floor, Jewelry Trade Center, 919/1 Silom Road, Bangkok 10500
Bangkok, Thailand
Specialty: Coloured stones, diamonds
Gemological Science International (GSI) Bangkok
Bangkok gem and jewellery district (street address not published)
Bangkok, Thailand
Specialty: Coloured stones, diamonds and lab-grown diamonds, jewellery, pearls
Guild Gem Laboratory (Thailand)
Room B25BC, B1 floor, Jewelry Trade Center, 919/1 Silom Road, Bangkok 10500
Bangkok, Thailand
Specialty: Coloured stones, diamonds
Gübelin Gem Lab Bangkok
Unit 211, Silom 19 Building, 45/1 Silom Road, Bangrak, Bangkok 10500
Bangkok, Thailand
Specialty: Coloured stones, diamonds, pearls; Gem Passport
Hanmi Gemological Institute & Laboratory
Seoul, South Korea
Specialty: Diamonds, gemstones
Hong Kong Jade & Stone Laboratory (HKJSL)
Hong Kong, Hong Kong SAR
Specialty: Jadeite (fei cui); ruby, sapphire, emerald, alexandrite
ICA GemLab
6th floor, Jewelry Trade Center, 919/7-8 Silom Road, Bangrak, Bangkok 10500
Bangkok, Thailand
Specialty: Coloured stones; origin and treatment detection
IGI Bangkok
BGI Building, 9 Soi Charoen Krung 36, New Road, Bangkok 10500
Bangkok, Thailand
Specialty: Diamonds, lab-grown diamonds, coloured stones, jewellery
IIGJ Lab (GJEPC)
Jaipur, India · also Mumbai
Specialty: Gemstones, diamonds, jewellery (formerly Gem Testing Laboratory, Jaipur)
Lotus Gemology
Silom 19 Building, Suite 411, 4th floor, 45/1 Soi Silom 19, Bangkok 10500
Bangkok, Thailand
Specialty: Ruby, sapphire, spinel; origin reports
National Gem & Jewellery Authority (NGJA)
Colombo, Sri Lanka
Specialty: Gem testing (national authority)
National Gemstone Testing Center (NGTC)
Beijing, China
Specialty: Gemstones, jade, diamonds, precious metals (national centre)
Middle East
Europe
Birmingham Assay Office
Birmingham, United Kingdom
Specialty: Precious metal testing and hallmarking; jewellery compliance testing
CISGEM
Milan, Italy
Specialty: Diamonds, coloured stones, pearls, coral
DSEF German Gem Lab
Idar-Oberstein, Germany
Specialty: Coloured stones, pearls, diamonds
Edinburgh Assay Office
Edinburgh, United Kingdom
Specialty: Precious metal testing and hallmarking
GGTL Laboratories
Geneva, Switzerland · also Balzers (Liechtenstein)
Specialty: Diamonds, coloured stones, pearls
GRS GemResearch Swisslab
Lucerne, Switzerland
Specialty: Coloured stones, origin reports
Goldsmiths' Company Assay Office
London, United Kingdom
Specialty: Precious metal testing and hallmarking
Gübelin Gem Lab
Lucerne, Switzerland · also Hong Kong, New York
Specialty: Coloured stones, pearls, origin reports
HRD Antwerp
Antwerp, Belgium
Specialty: Diamonds, lab-grown diamonds
International Gemological Institute (IGI)
Antwerp, Belgium · also About 30 laboratories worldwide, incl. New York, Mumbai, Hong Kong, Bangkok, Dubai
Specialty: Diamonds, lab-grown diamonds, coloured stones, jewellery
Laboratoire Français de Gemmologie (LFG)
Paris, France
Specialty: Diamonds, coloured stones, pearls
SSEF Swiss Gemmological Institute
Basel, Switzerland
Specialty: Coloured stones, pearls, diamonds; origin and research
Sheffield Assay Office
Sheffield, United Kingdom
Specialty: Precious metal testing and hallmarking; analytical services
Americas
American Gemological Laboratories (AGL)
New York, United States
Specialty: Coloured stones, origin reports
CDTEC GemLab
Bogotá, Colombia
Specialty: Emeralds, coloured stones, diamonds; treatment and origin
Gem Certification & Assurance Lab (GCAL)
New York, United States
Specialty: Diamonds
Gemological Institute of America (GIA)
Carlsbad, United States · also New York, Mumbai, Surat, Bangkok, Hong Kong, Tokyo, Ramat Gan, Antwerp, Gaborone, Dubai
Specialty: Diamonds, lab-grown diamonds, coloured stones, pearls
Gemological Science International (GSI)
New York, United States
Specialty: Diamonds, lab-grown diamonds, gemstones
Africa
E.G.L. South Africa
Johannesburg, South Africa
Specialty: Diamonds, coloured stones incl. tanzanite, jewellery
Oceania
Listed alphabetically within each region. JewelLoop does not rank, recommend or endorse any laboratory. Details come from each laboratory's own website; check services and fees with the laboratory directly.