All about gemstone treatments including heating, bleaching, surface coating and more.

Center-fused Color Treated Gemstones

Earlier this year a new gem treatment was introduced, called “center-fused color treatment,” it may sound confusing at first, but it is actually simple.

Corundum Treatments

Many techniques have been developed to enhance the appearance of Corundum gems. Some of the treatments are very subtle, invisible even with a loupe.

Difficult Gemstone Separations

Two of the trickiest gemstone separations to make are scapolite from citrine and apatite from tourmaline. Learn some tips for distinguishing these gems.

Disclosing Enhancements: A Gemologist's Guide

Disclosing enhancements to gems is a key duty for gemologists. Learn what are the hardest treatments to detect and how to report your findings clearly.

diffusion treated gems - detail sapphire
How to Test for Diffusion Treated Gems

Learn how to spot diffusion treated gems with a simple immersion test. This common treatment for sapphire gems significantly reduces their value.

Identifying Inclusions Found in Enhanced Gems

When Identifying Inclusions found in Enhanced Gems, you have to be very careful when inspecting your stones. A clue is to find bubbles in the glue layer.

A Beginner's Guide To Common Gemstone Heat Treatments

Gemstone heat treatments can increase the beauty and value of many rough pieces. Learn how to conduct the most common procedures safely.

Aquamarine Color and Heat Treatment

There's more to aquamarine color than blue. Most natural stones start blue-green and are heated to blue. Learn the pros and cons of this treatment.

emerald treatments - ring
A Consumer's Guide to Emerald Treatments

Emerald treatments, such as oiling, are very common. Learn what these techniques do, how emeralds are graded, and what green gems make great alternatives.

gem buyers - custom cut tourmalines
How Can Gem Buyers Protect Themselves from Fraud?

How can gem buyers avoid undisclosed gem treatments and substitutions? Learn why it's best to deal with expert gem cutters rather than commercial dealers.

gem treatment survey results - leaded glass ruby - blue flash off fissues and air bubbles
Gem Treatment Survey: Is this Gem Natural?

We've tallied your opinions from the International Gem Society gem treatment survey. Are treated gems natural? How much should they cost? With a wide variety of attitudes toward gem treatments, what can we do to educate the public and to encourage treatment disclosure?