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 ...

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 ...

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 ...

Colorless to yellow to intense orange sapphire will react quite differently to light or heat depending on the nature of the material and the origin of the color. The authors determined that there 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 ...

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 ...

In November 2022, a parcel of 24 approximately 0.5–1.2 ct spinel crystals, described as cobalt-diffused, were obtained directly from a treater by the research team at GIA in Bangkok. Of these, seven ...

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 ...

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 ...

Originally published in GemGuide in 2016, this comprehensive series examines the quality factors that influence the value of colored gemstones, with a specific emphasis on the role cut quality plays ...

Once upon a time, gem cutting was a strict craft bound by centuries of tradition. The job of a lapidary was to cut a gemstone to ideal proportions while preserving as many carats as possible. Then ...

Gem inclusions are mineral crystals or cavities filled with fluid and/or gas that occur in a host gemstone. Many gems contain microscopic inclusions (ranging in size from >1 mm down to submicroscopic ...