Education

The WGI Knowledge Centre.

Clear, expert guidance on diamonds, gemstones and jewellery — from the 4Cs to reading your WGI report.

Grading

Diamond Grading & the 4Cs

Cut, colour, clarity and carat weight — the universally recognised criteria for evaluating a diamond.

Read the guide

Lab-grown

Lab-Grown Diamond Technology

How CVD and HPHT diamonds are grown, and how laboratories identify them.

Identification

Natural vs Synthetic Gemstones

Why telling nature's work from a laboratory's requires specialised testing.

Reports

How to Read a WGI Report

A guide to the information on your WGI report or card, and how to verify it online.

Glossary

Jewellery Terminology

The words you will see on reports and in jewellers' showrooms.

Care

Caring for Fine Jewellery

Simple habits that keep diamonds bright and settings secure.

Value

Understanding Evaluation & Valuation

The difference between grading an item and estimating its value.

FAQ

Frequently Asked Questions

Answers to common questions about WGI reports, cards and verification.

World Gemological Institute

Discover 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.

Contact WGI Explore Our Services