One of the most famous gems in the world, The Hope Diamond is a 45.52 carat Fancy Deep grayish blue diamond. GIA researchers examined it in 1988. Photo: Chip Clark, courtesy of Smithsonian Institution ...

Results from spectroscopic analyses of GE POL high-pressure high-temperature (HPHT) annealed nominally type IIa diamonds are presented, and these spectral characteristics are compared with those of ...

A potential new synthetic gem material in the form of a faceted 0.88 ct brownish yellow nano-polycrystalline diamond (NPD) has undergone a full gemological examination, including detailed ...

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 ...

Figure 1. Pleochroism in a 15 ct tanzanite, as seen with the unaided eye through the crown and the pavilion sides and ends. Photo by Wimon Manorotkul. In describing colored gemstones, the major ...

CARLSBAD, California – January 14, 2025 - The Gemological Institute of America (GIA) has announced the planned retirement of its president and CEO, Susan Jacques, at the end of 2025. The Institute has ...

Studies concerning the origin of color in gem materials have grown in sophistication in recent years, so that much new information is now available about natural color and its possible modification by ...

Renewed interest in large-scale commercial mining of Montana sapphires motivated a detailed study of the heat treatment of sapphire from the Rock Creek deposit. During the course of this systematic ...

As a consumer, you will regularly encounter in the marketplace gems that have been treated to change their appearance. A topic that often comes up is whether a particular gemstone is or isn’t treated.

This 15th-16th century icon of Mexican (Aztec) art, was probably worn on the chest on ceremonial occasions. ©The Trustees of the British Museum Turquoise is one of the world’s most ancient gems.

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.

The Jewelry Design & Technology diploma program covers topics essential to becoming a jewelry designer and CAD (computer-aided design) technician, including designing a piece of jewelry from a concept ...