The Karowe Diamond Mine in Botswana, owned and operated by Lucara Diamond Corp., has gained international recognition for producing large, high-quality type IaB or coexistence of IaB with IIa diamonds ...

CARLSBAD, Calif. – June 2, 2025 – Beginning later this year, GIA (the Gemological Institute of America) will start using descriptive terms to characterize the quality of laboratory-grown diamonds and ...

View the holiday schedule for all GIA locations worldwide.

This large Australian light opal cabochon weighs 117.85 carats. Small play-of-color flashes of orange and green predominate in a pinfire pattern, with spots of a more muted blue over a grayish ...

Diamond color is usually the result of selective absorption of incident white light. The unabsorbed portion of this light is transmitted through the diamond and is interpreted by the human vision ...

Practice the same time-tested procedures and identification skills used by the Institute’s renowned gemological experts. Tools used include a microscope, a refractometer with polarizing filter and a ...

Figure 1. The bright red faceted ruby in this gold ring is from the large and potentially productive Snezhnoe deposit in Tajikistan. Photo by Zamoniddin Z. Nasriddinov. Discovered during the late ...

For the first time ever, the famous Hope diamond was graded by a widely recognized system. Although the 45.52-ct weight was confirmed, the GIA Gem Trade Laboratory graders found the clarity—recently ...

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 ...

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 ...

Tutti Frutti (bold color contrasts using carved gemstones) dazzles in this bracelet, brooch, and lapel watch by Mauboussin. Jewelry courtesy of Kathryn Bonanno. The Roaring Twenties – It’s a time that ...

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 ...