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A large group of people outside on GIA’s Carlsbad, California campus.

Article

Guardians of Trust: GIA’s Innovative Research, Instruments and Services

Russell Shor, September 20, 2019

GIA’s services and instruments have grown in importance and impact as new gem treatments and laboratory-grown gems have entered the market.

Alexandrite cabochon in fluorescent (left) and incandescent light (right).

Cat’s-Eye Alexandrite with Unique Inclusion Pattern

Makoto Miura and Yusuke Katsurada, January 26, 2018

Examination of a chatoyant alexandrite cabochon.

Three pieces of labradorite with yellow, blue and green flashes of color.

Article

Optical Effects of Phenomenal Cabochons

Sharon Bohannon, November 11, 2016

Learn how the structure, inclusions and properties of some gemstones interact with light to create unusual visual effects.

Article

Shenzhen: The Frontier of China’s Gem and Jewellery Industry

Tao Hsu, January 25, 2016

All jewellery professionals are familiar with the city of Shenzhen, a global jewellery manufacturing centre and a leader of China’s fast-growing gem and jewellery industry. Join the GIA team as we tour the city and discover more about its leading jewellery brands.

The superior size and color of the 325.13 ct. tsavorite garnet from Merelani was discovered at the Tucson Gem & Mineral show in 2007. Courtesy of Michael Couch & Associates, West Des Moines, Iowa; photo by Robert Weldon © GIA

Article

The Glory of Green Gems

Sharon Bohannon and Peggy Tsiamis, June 12, 2015

Green gemstones, which can uplift and heal our spirits, have been popular gem choices ever since we began to adorn ourselves with jewellery.

Article

Gemmologist’s Black Opal Ring Wows Consumers and Trade Media

Jaime Kautsky, May 8, 2015

GIA graduate Niveet Nagpal, president and head designer of Omi Privé, showcases his love of gems and brings them to life in his designs.

Figure 1. The two purple to reddish purple chrysoberyl samples from Brazil studied (left images) and two “normal” alexandrites from Hematia, Brazil (right images) in daylight (top) and incandescent light (bottom) illustrate the lower blue-green transmission with increased trivalent chromium. Photos courtesy of Karl Schmetzer.

“Red” Chrysoberyl versus Alexandrite: The Impact of Elevated Chromium Levels on Colour and Colour-Change Properties

Jennifer Stone-Sundberg , October 31, 2014

Overview and commentary on the 2014 Journal of Gemmology article “Purple to Reddish Purple Chrysoberyl from Brazil”.

Record-Size Natural Moissanite Crystals Discovered in Israel

Emmanuel Fritsch, Vered Toledo, and Antoinette Matlins, July 25, 2014

Natural moissanite crystals found in Israel has broken world records, with evidence of larger crystals in the area.

14 ornaments of coral veneer glued to matrix

Composite Coral Veneer Glued to Artificial Matrix

Haibo Li, Zhoujing Yue, Jie Liang, Taijin Lu, Jun Zhang, and Jun Zhou , July 25, 2014

Items presented as red coral are revealed by testing to be composite coral veneers over an artificial matrix.

Prasiolite with Brazil-law twinning in optic-axis direction

Prasiolite with Inclusion Influenced by Brazil-Law Twinning

Meenakshi Chauhan, July 25, 2014

A prasiolite specimen displaying Brazil-law twinning, usually seen in the amethyst variety of quartz, is examined.

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