The Science Behind Every Sparkle.
Confidence in Diamonds. Excellence in Gemology.
Discover the world of professional diamond grading, lab-grown diamonds and fine jewellery with World Gemological Institute.
A Legacy of Expertise. A Commitment to Excellence.
World Gemological Institute is an international gemological laboratory specialising in the identification, examination and grading of diamonds, gemstones, pearls and jewellery.
In 2016, WGI moved its headquarters from the Israel Diamond Exchange in Ramat Gan to a new laboratory in the heart of London's diamond district, Hatton Garden. Our gemologists, graduates of the Gemological Institute of America (GIA), combine extensive industry experience with modern laboratory equipment and independent analysis.
WGI takes a conservative approach to grading, delivering dependable consistency to every client — from private buyers to retailers, manufacturers and dealers.
Lab-Grown Diamonds. Real Brilliance. Scientific Confidence.
Laboratory-grown diamonds possess essentially the same chemical, physical and optical properties as natural diamonds. Because they look identical to the eye, reliable identification, testing and grading are essential for everyone who buys, sells or wears them.
Carbon from an energised gas settles onto a diamond seed, layer by layer, growing a crystal.
The extreme pressure and heat of the earth's depths are recreated so carbon crystallises onto a seed.
Growth patterns, fluorescence and spectroscopic signatures reveal how a diamond formed — distinguishing laboratory-grown from natural.
Expertise in Every Facet.
Independent reports that help consumers and the trade understand exactly what they are buying, selling or wearing.
Your Jewellery. Your WGI Record.
Enter the certificate number printed on your WGI card, or scan its QR code, to see the official online record of your jewellery.
Your certificate connects you to the official WGI record, where you can review the details recorded for your jewellery.
Where Expertise Meets Integrity.
Professional gemologists
GIA graduates who pursue continuing study, including the Gem-A Fellowship (FGA).
Independent analysis
No vested interest in the outcome — fair, unbiased and conservative grading.
Modern technology
Continual investment in instruments, including FT-IR spectroscopy.
Detailed reports
Diamond, jewellery, gemstone, pearl and watch reports.
International experience
Offices in London, New York and Ramat Gan serving the global trade.
Online verification
Every report carries a unique number that can be verified online.
Precision You Can Trust.
WGI's grading processes are updated according to the latest industry developments, using testing standards and equipment in line with the industry's latest techniques.
- 01
Diamond examination
Each stone is cleaned, weighed and examined under controlled lighting.
- 02
Microscopy
Inclusions, growth features and surface characteristics are studied under magnification.
- 03
Diamond measurement
Calibrated instruments record dimensions and proportions.
- 04
Gemstone identification
Optical and physical properties establish species and treatments.
- 05
Natural vs laboratory-grown
Specialised equipment and FT-IR analysis reveal a stone's origin.
- 06
Report preparation
Findings are reviewed and recorded in a report with an online verification number.
International Expertise. Professional Standards.
WGI offers professional gradings and evaluations to the global jewellery industry, with its laboratory in London and offices serving the trade in New York and Ramat Gan.
London
100 Hatton Garden, Suite 207, London EC1N 8NX, United Kingdom
info@wgi-global.comRamat Gan
1 Jabotinsky Road, Maccabi Building, Diamond Exchange, Suite 1253, Ramat Gan, Israel
israel@wgi-global.comDiscover the Confidence of WGI.
Whether you are exploring lab-grown diamonds, seeking professional gemological services or learning more about your jewellery, discover the expertise behind WGI.