Established in 1931, the Gemological Institute of America (GIA) is the world’s foremost authority on diamonds, colored stones, and pearls. A public benefit, nonprofit institute, GIA is the leading ...

The 75.47-carat Hooker Emerald was worn by Ottoman Sultan Abdul Hamid II, the last sultan of the Ottoman Empire. Photo by Chip Clark, courtesy Smithsonian Institution, National Museum of Natural ...

Despite the commercial value of natural-color diamonds, distinguishing them from treated diamonds remains a significant identification challenge. While some diagnostic visual features exist ...

Malaya garnets from Bekily, Madagascar, are predominantly pink to pinkish orange, with some stones orange to red. Discovered only in the late 1990s, the majority are intermediate members of the pyrope ...

Although lost for literally hundreds of years after the Spanish conquest of the Aztecs, many deposits of jadeite have been found in Guatemala during the last two decades. Following the discovery of ...

Studies carried out at the DTC Research Centre have shown that single-crystal CVD synthetic diamond is clearly distinguishable from natural diamond. This article presents information about the CVD ...

Figure 1. These emeralds from Musakashi, Zambia, range from 0.57 to 4.85 ct. The rough samples were polished with one window on each. The faceted sample measures 6.29 × 5.35 × 3.53 mm and weighs 0.97 ...

Figure 1. These 20 completely non-nacreous pen pearls, from the group of 22 samples in this study, are set against a pen shell displaying both nacreous (left) and non-nacreous areas (right). Photo by ...

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.

A look at the history of analytical instruments used for gem testing. UV-Vis-NIR spectroscopy measures how gemstones absorb and interact with light across the ultraviolet, visible, and near-infrared ...

The Graduate Jeweler diploma program is a hands-on experience that introduces students to the knowledge and skills required for a career in jewelry fabrication and repair. You will work with gemstones ...

If you were born in the month of June, you are lucky enough to have three birthstones to call your own. June is one of only three months (the others are August and December) that has three birthstones ...