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 ...

Cultured pearls come in different sizes, shapes, and colors. Perhaps the best-loved gems of all time, pearls—both natural and modern cultured pearls—occur in a wide variety of colors. The most ...

The discovery of significant quantities of gem-quality sapphire in Minas Gerais could add corundum to the formidable list of gem species already commercially produced in Brazil. The presence of ...

GIA is the creator of the 4Cs of diamond quality and the leading research and education center for gems and gemology. Considered the world authority on gems, the Institute is open to the public Monday ...

Few people outside the gem industry realize the true nature of a gemstone’s journey from the mine to the counter of a store. Whether the gem is being offered to consumer’s at a traditional jewelry ...

Figure 1. This 2.07 ct oval brilliant is the first faceted milarite examined by the Carlsbad lab. Photo by Diego Sanchez. Recently the Carlsbad lab received a light yellow 2.07 ct unknown gemstone ...

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 ...

Lapis lazuli might be dyed to improve its color and conceal any calcite inclusions. Lapis that hasn’t been dyed might be impregnated with wax or oil to improve color and luster. These treatments have ...

With 65,000 volumes, 230,000 images, 2200 videos, and 1200 periodicals, the Richard T. Liddicoat Gemological Library & Information Center and Cartier Rare Book Repository & Archive is the largest, ...

Diamonds have a long history as beautiful objects of desire. In the first century AD, the Roman naturalist Pliny stated: “Diamond is the most valuable, not only of precious stones, but of all things ...

GIA does not unmount and remount stones. However, Colored Diamond Identification and Origin Report service and most identification services for colored stones and pearls can be performed on mounted ...

Diamond is available in a range of sizes and qualities to fit every consumer's tastes. One of the first things most people learn about diamonds is that not all diamonds are created equal. In fact, ...