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 ...

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 ...

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 ...

Descending into Peshawar for the first time, a foreign tourist might be surprised to learn that amid the clutter of buildings in this historical city lies an important gem trading center. This market ...

Tanzanite is one of the most popular colored gemstones in the world.- Courtesy Tanzanite Foundation ™ Tanzanite is a versatile gemstone that comes in a variety of sizes and cutting styles. Although it ...

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 ...

Through extensive hands-on practice using gemstones, you will explore grading the color, clarity and cut quality of a wide range of colored stones. Coursework includes the study of the GIA Colored ...

Soon after it was first marketed in 1976, colorless cubic zirconia became the dominant diamond imitation, with current production of approximately 60 million carats per year. Although cubic zirconia ...

GIA has studied more than 400 important gemstones in the Edward J. Gübelin Gem Collection and is committed to sharing this repository of gemological information. Dr. Edward Gübelin’s lifelong study of ...

Gem-quality spessartine garnet and grossular garnet have been discovered in Altay, China. Gemological and mineralogical studies show that their properties are typical for these garnet species.