What Do the GIA Gem Clarity Grading Codes Mean?
A gemstone’s clarity grade indicates how free it is of inclusions and blemishes. Learn how to decipher the GIA clarity grading codes and types.…
Common Gemstone Treatments Cheat Sheet
There are so many common gemstone treatments available today that keeping track of them can be difficult. This list and handy cheat sheet can help.…
Emerald Origins
Although emeralds occur in many localities, some sources are better known for high-quality gems than others. Learn about famous (and not so famous)…
Gemstone Radiation Treatment
Gemstone radiation is a common but little understood technique for altering colors. Learn how it works and what gems usually receive this treatment.…
Carving Techniques for Handling Inclusions in Transparent Gems
Inclusions don’t have to result in a loss of mass or value when cutting transparent gems. Learn how to manage inclusions with basic gem carving techniques.…
Gemstone Magnetism: The Forgotten Property
Although gemstone magnetism isn’t commonly tested, it can help gemologists distinguish similar looking gems. Learn how to analyze this property.…
Are White Aquamarines Genuine Aquamarines?
Aquamarine is the blue to blue-green variety of beryl. If you encounter so-called white aquamarines, buyer beware. Learn the facts about these…
Table of Gems Ordered by Crystal System
This table contains a selection of minerals gemologists may encounter as jewelry stones or gem specimens. The gems are sorted by their crystal…
Specific Gravity Values of Selected Gems
Measuring specific gravity helps gemologists identify gemstones. The following table lists the specific gravity values for a variety of gem…
IGS Become Member