Birmingham Assay Office
Birmingham, United Kingdom
Specialty: Precious metal testing and hallmarking; jewellery compliance testing
Gem laboratories
Laboratories that test and grade diamonds, coloured stones and pearls, and assay offices that test precious metals, around the world.
Europe
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
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.