Natural pearl identification is one of the critical problems in pearl research. The DNA study of pearly mollusks and oysters facilitates solving this problem. To fulfill this goal, GIA sent a group ...

While more people are becoming familiar with lab-grown diamonds, many still don’t know how they are actually made. Learn about the two diamond growth processes, HPHT and CVD.

GIA researchers report on a new nickel-diffusion treatment used to modify color in spinel and present criteria for identification.

Carbon is one of the most important elements on our planet, which led the Geological Society of London to name 2019 the Year of Carbon. Diamonds are a main host for carbon in the deep earth and also ...

Reports on a visit to a shell nucleus manufacturer and two pearl farms in northern Vietnam, which is emerging as a notable producer.

A behind-the-scenes exploration of the Smithsonian's Janet Annenberg Hooker Hall of Geology, Gems, and Minerals.

Diamonds have a long history as a premier gemstone—a natural consequence of their beauty, rarity, and superlative physical properties such as extreme hardness. Diamonds that are mined for use as ...

Lightning Ridge is the world capital of fine black opals, the most desired of all opals. In June 2015 a group of GIA field gemologists visited this legendary town in New South Wales, Australia. Come ...

A highly saturated purplish pink to red pezzottaite from a new deposit in Madagascar is encountered in Tucson and tested by GIA researchers.

Journey with us to Brazil for a visit to one of the world’s most prolific tourmaline mines. You’ll also hear a highly captivating story of family success through perseverance.

Figure 1. This 0.86 ct gray musgravite displays an unusual iridescent phenomenon that is clearly visible in the table facet. Photo by Kevin Schumacher. Musgravite is a rare mineral closely related by ...

Learn about the differences – and similarities – between natural and laboratory-grown diamonds, and how GIA’s researchers and grading laboratories can tell the difference ...