Nephrite jade with high market value and production potential from the Chinese city of Hechi, in Guangxi Province, was tested by standard gemological methods, polarizing microscopy, scanning electron ...

Diamond “type” is a concept that is frequently mentioned in the gemological literature, but its relevance to the practicing gemologist is rarely discussed. Diamonds are broadly divided into two types ...

The soothing soft pink shades of rose quartz appeal to gem carvers and collectors. – Valerie Power, courtesy Arunashi People accept a certain amount of sand, dirt, and dust as ordinary ingredients in ...

Many of the important gem minerals seen on today's market - aquamarine, tourmaline, and topaz, among others - come from an unusual type of rock known as a pegmatite. Gem-bearing pegmatites are ...

Whether you’re taking the next step in your professional journey or starting a new career, GIA courses and diploma programs prepare you for success. We offer the finest gem and jewelry education in ...

GIA’s laboratory in Bangkok, Thailand conducts research and provides services such as diamond grading and origin determination, colored stone grading and origin determination and pearl identification ...

North America has a long history of natural pearling owing in part to its very diverse and rich freshwater mussel resources. After the Civil War pearl jewelry gained greater popularity in the United ...

Figure 1. Glass in a silver brooch, hallmark from 1866. Private collection, photo by Jaroslav Hyršl. Tectites are members of a large group of impact glasses, formed by the collision of a meteorite on ...

Diamonds are known for their hardness – their ability to resist scratches and abrasions. But diamonds are not impervious to damage, since their hardness is uneven along different crystal directions.

This raspberry-and mint-colored tourmaline—nicknamed the “Steamboat”—is one of the world’s finest and most valuable mineral specimens. Photo by Duncan Pay ...

Figure 1. Sapphires from Madagascar: a beautiful 3.29 ct untreated faceted stone and an assortment of rough in the background. Madagascar has produced many high-quality stones in the last few years ...

Vietnam is a land of great diversity and beauty. From the hustle and bustle of Ho Chi Minh City to the beauty of Hạ Long Bay and Hoi An (both UNESCO World Heritage Sites), there are innumerable places ...