An Introduction to Gemology

Discover the fascinating geological journey that transforms colorless quartz into vibrant purple amethyst through volcanic processes, iron impurities, and natural...

As a December birthstone, blue zircon is very popular. But are blue zircons natural? Learn how zircons form and get...

Jedi spinel makes a beautiful jewelry stone. Learn how it got its name and what qualities make this vivid pinkish...

Turquoise gems can show many beautiful variations. Learn how turquoises form and how geology affects their color, shape, and durability....

Over six thousand years ago, the ancient Egyptians created beads made of silver and inscriptions indicate that it was worth...

For centuries, balas rubies were prized by royalty. Learn what happened after gemologists identified these gems as red spinels instead....

Available in many colors, spinels are becoming more popular with consumers. Learn how spinels form and how these gemstones get...

Learn how gemologists identify cobalt spinels and what qualities you should look for when buying these beautiful, vivid blue gemstones....

Jade color trade names describe prized hues and patterns in jadeite and nephrite stones. Learn about the most popular and...

Learn everything you need to know about maw sit sit, a rare, vibrant green gem rock used to make beautiful...

The minerals known as jade, jadeite and nephrite, appear similar but have different properties. Learn how these materials form geologically....

Should you wear chrysoprase jewelry only at night to protect the gem’s striking green color? Learn the facts here.

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

Gem identification is part detective work, part art. Learn how gemologists can distinguish gem species and determine whether a stone...

Learn how lab grown sapphires are made and how gemologists can distinguish natural from synthetic sapphires.

Many consumers don’t understand the difference between natural pearls and cultured pearls. Learn what these terms mean and how to...

We live in a world of crystals. Learn what they are and where you can find them, from deep underground...

Discover America's best gem hunting locations where you can unearth emeralds, diamonds, sapphires and more! Plan your gemology vacation with...

Gem formation usually involves mineral crystallization and other geological processes. Learn how these affect the gemstone properties gemologists study.

Gemstone inclusions are materials trapped inside gems as they form. Learn how gemologists use inclusions to help identify gemstones and...

Crystals have habits. In crystallography, mineral habits refer to the way crystals form within a specific mineral. There are six...

Explore gemstone hardness, wearability, and durability. Learn how hardness, cleavage, and settings affect jewelry use. Essential for smart gemstone choices....

Are opals too delicate for jewelry? Learn how to choose the right settings for opal wearability, so you can enjoy...

Learn how to organize your gemstone collection. Choose the storage and display options that are right for you and create...

What do you know about birthstones? Take our short birthstone quiz and learn about the makeup, cutting, and value of...

Although many gem enthusiasts want to become collectors, they may not know where to begin. Read this article for tips...

Chemical formulas identify the chemical composition of minerals, including gems. Learn what their symbols, numbers, and parentheses mean.

Gemstone luster describes how a gem's surface looks when it reflects light. Learn the common terms gemologists use for this...

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

Gemologists use several different gem classification methods. Learn how the most common systems work and what they cover as well...

Learn the difference between allochromatic and idiochromatic gems and why some gem species can occur in many color varieties and...

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

Learn what gemstone dispersion means, what causes it, and how it relates to other optical effects.

Gem species are mineral species prized for their durability and beauty. Learn how chemical formulas and crystal structures define species...

The March birthstone, aquamarine is a popular gem. Learn how aquamarines form, what they look like, and how they get...

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

Identifying gemstone treatments is difficult even for experienced gemologists. Learn about the many different ways gem color and clarity are...

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

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

Learn how gems absorb wavelengths of light and how gemologists use gemstone absorption spectra to identify gems. There’s more to...

Gemstone identification requires a good reference library and some basic gemology tools. Before you go shopping, learn more about what...

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

A versatile gem and the famous January birthstone, garnet is a favorite among jewelers and consumers. Learn how garnets form...

A little gemology goes a long way. Learn how to clean your gemstone jewelry safely and how to deal with...

Quartz is one of the most abundant minerals on earth. Learn how quartz forms and how its most popular varieties...

Topaz requires specific and unusual conditions to form. Learn how topaz develops and how it gets its colors, from yellow...

Learn about tourmaline formation, where tourmaline is found, and the unusual geological conditions that give this stone its fantastic colors....

How do emeralds form? Learn how the emerald growth process works and why it makes these gems rare, green, and...