By contrast, the pearls sometimes labeled as “Chinese akoyas”, “baby akoyas”, or “freshwater akoyas (AK)” are freshwater ...

Diamonds are the most amazing of gems. Just as amazing, however, is how natural diamonds reach Earth’s surface. Diamonds are formed 150 to 700 km deep in Earth, and are then carried upward in a rare ...

Figure 1. This demantoid was faceted to better reveal the “horsetail” inclusions. The sample is 8 mm in diameter. Photo by U. Hennebois. The exact origin and composition of the “horsetail” inclusions ...

If you're attending AGTA in person, take the quiz corresponding to the day you're visiting. Each daily quiz is based on the specific minerals displayed at the GIA booth that day, giving attendees a ...

GIA Student Workrooms give you affordable access to all the equipment and gemstones you need to complete the practical requirements of your Gem Identification course through Online Education. This ...

An 11.23 ct purplish pink cabochon exhibiting multiple cat’s-eye phenomena was recently submitted to the Tokyo laboratory for identification (see above, left). Standard gemological testing results ...

With the withdrawal of Soviet troops from Afghanistan, villagers in the Panjshir Valley are turning their attention to the emerald riches of the nearby Hindu Kush Mountains. Large, dark green crystals ...

GIA offers many opportunities for students to receive a scholarship. Scholarship offerings are made available to assist eligible students in reducing their financial burden and focusing on completing ...

The Diamond and Diamond Grading eLearning course brings to life the skills needed to grade the color, clarity and cut of diamonds through video, graphics, images and text.

The red variety of the mineral tugtupite, a rare silicate closely related to sodalite, has been used as a gemstone since 1965. This article presents the history of the mineral and details of its ...

Although GIA is most recognized as the world’s foremost authority in diamond grading, it has been a leader in the identification and classification of natural and cultured pearls since 1949. GIA has ...