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 ...

Figure 1. Top left: Rubies are mined in a mango orchard in Channapatna, India. Top right: This 15 kg rough ruby is from Subramaniam, in the Indian state of Karnataka. Photos by Pooja Shirole. Bottom ...

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 ...

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.

One of the greatest concerns with emerald filling is the degree of clarity enhancement such treatment represents. Stones that appear to have excellent clarity with the unaided eye are often revealed ...

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.

The popular GIA Graduate Jeweler program blends a foundational technical education with the practical skills needed in the modern jewelry industry while encouraging students to express their ...

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 ...