Birthstones are a fun, popular and colorful introduction to the world of gemstones. They appeal to audiences around the world regardless of gender, age, nationality or religion. Birthstones carry ...

This 32” x 20” wall chart presents GIA’s system for classifying pearl quality according to the seven factors of size, shape, color, luster, surface, matching, and nacre.

Major rock units of the Neyshabur mine are divided into three groups: volcanic, subvolcanic intrusions, and hydrothermal breccia (Ghiasvand et al., 2017). Although the volcanic rocks of trachyte and ...

Explore diamond history, research, quality factors, and more in the GIA Gem Encyclopedia.

Within a short time, 90 more claims appeared in the same 20-square-mile area. No one was quite sure what the beautiful crystals were, but everyone wanted to lay claim to the profits they were certain ...

Explore pearl history, research, quality factors, and more in the GIA Gem Encyclopedia.

Field reports, videos, photography, and firsthand accounts from mines and industry hot spots around the world.

The quarterly journal of the Gemological Institute of America.

colored stone research The microscope is one of the most important tools for a careful gemologist. Unbeknownst to the casual observer, there exists a fascinating and visually stunning microscopic ...

The market value of jadeite has risen dramatically in recent decades, often rivaling that of fine ruby and sapphire. Understanding the color origin of jadeite and reliably determining treatments have ...

During the Middle Ages, sapphires and rubies initially adorned the engagement ring, while diamonds were incorporated in the 15th century. The earliest written record of the use of a diamond in an ...

Global Database - Gem grading and identification records are archived in an extensive global database for ongoing study and future reference. This information gives GIA the ability to identify items ...