Learning Center

An Introduction to Gemology

The basic building blocks of understanding the science of gemstones.
Freshwater Cultured Pearls

As consumers compare price and quality, freshwater cultured pearls are rapidly becoming more popular than Akoyas. Learn more about these amazing…

How Do Pearls Form?

Do pearls form around grains of sand trapped in oysters? Learn the facts about pearl formation and the various mollusks that create these organic…

How Do Opals Form?

Curious about how opals form and show such stunning colors? Learn about the scientific theories behind opal formation and why some opals show a…

Gemology Career Options

Thinking of becoming a gemologist? Consider these gemology career options, compare their estimated salaries, and decide which one may be right…

An Introduction to Gemology

Learn what gemologists do in our introduction to gemology. Whether your interest is casual or professional, the world of gems will amaze you.

What is Gemstone Transparency?

Gemstone transparency describes how much light passes through a gem and how it scatters. Learn what causes a gem to be opaque, translucent, or transparent.…

A Brief History of Diamonds

Learn how diamonds formed geologically and how they became the virtual standard for engagement ring stones in this brief history of diamonds.…

Top Spots for Gem Hunting in the US

Visit one of the top gem hunting spots in the US. Go alone or with the family. A gemology-themed vacation can be fun, educational, and (maybe) profitable.…

What is Gemstone Birefringence?

Gemstone birefringence is a measure of a gem’s double refraction. Learn how it’s used to identify gems and see the effects birefringent gems…

A World of Crystals

We live in a world of crystals. You don’t have to dig deep into the Earth to find them. Even the bones in our bodies and the dust in the air contain them.…

An Introduction to Fancy Gem Cuts

Although rounds and other standard shapes dominate the gemstone market, fancy gem cuts offer many beautiful alternatives that can also improve…

A Guide to Gem Cutting Styles

Gem cutting styles refer to the shape and arrangement of facets. The three most basic styles are brilliant, step, and mixed. Learn what characterizes…

How to Start a Gem Collection

Although many gem enthusiasts want to become collectors, they may not know where to begin. Read this article for tips on how to start a gem collection.…

Trapiche Gems: An Introduction

Satisfying the human desire for symmetry, trapiche gems have a special allure. Learn what makes these rarities so unique in our introductory article.…

What is a Crystal?

Learn the scientific definition of crystal used by gemologists and answer some basic questions about what is and is not a crystal.

Mechanical Gemstone Cleaning

Mechanical gemstone cleaning has benefits and risks. Learn all about ultrasonic, steam, and boiling systems and how gems might react to them.…

Gemstone Care Guide

Our gemstone care guide covers many popular gems. Learn how best to maintain your gemstone jewelry and what kinds of stresses and cleaning methods…

What is Gemstone Luster?

Adamantine. Silky. Greasy? Gemologists use these and other evocative terms to describe gemstone luster. This simply means how a gem’s surface…

What is a Gem?

Even the most general definition of a gem has many exceptions. Learn what qualities have been used to identify gemstones both scientifically and…

A Guide to Gem Classification

There is not one way to classify gems, rather there are several ways, each of which has its own purpose and its own exceptions that warrant close attention.…

Sphalerite Appraisal

Learn what factors most influence a sphalerite appraisal and what kind of jewelry will best showcase this beautiful gemstone.

Opal Jewelry Tips

Opal jewelry is lovely, but aren’t these gems prone to scratching and breaking? Learn the best ways to wear these colorful but delicate stones.…

What Is A Reflectometer?

What’s the difference between a reflectometer and a refractometer? If you’re interested in studying or buying gems, learn the facts here.…

Australian Opals

Australian opals account for 95% of the world’s supply. Learn about Australia’s geological history, the start of its opal trade, and its sources.…

Build Your Own Gemology Tools

Are you a hobbyist or professional gemologist facing high equipment costs? Read our IGS series of articles that can help you build your own gemology…

Spectroscope Instructions

The spectroscope is one of gemology’s principal tools. Our basic spectroscope instructions will teach you how to operate and calibrate this…