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 ...

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 ...

Blue sapphires are currently being mined on an exploratory basis from alluvial deposits at the Lindi mine, near the town of Mingxi in Fujian Province. The geology and occurrence of the sapphires ...

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 ...

The refractive indices of the synthetic overgrowth on the beryl seeds of Lechleitner synthetic emeralds show a linear correlation with the chromium content of the coating. In a sample with refractive ...

Citrine is one of the most popular yellow gems on the market. This designer cut shows off the warm glow of citrine’s sunny color. – Lydia Dyer, gem courtesy John Dyer & Co. Citrine—the transparent, ...

This sapphire from Kashmir has an intense velvety blue color. – Photo: Robert Weldon/GIA. Sapphire is one of the Big three of jewelry colored gemstones—the other two are ruby and emerald. A durable ...

This 5.30-carat emerald from Brazil has a slightly bluish green color. Courtesy John Parrish, courtesy African, Brazilian, Colombian Gems Incorporated. Emerald has many special qualities, but colored ...

オズの魔法使いの50周年を記念して、ハリー·ウィンストンは4600のルビーが設置された本物のルビーのスリッパを作成しました。 - Harry Winston(ハリー・ウィンストン)提供 赤は、私達の最も ...

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, ...

GIA instructors are passionate educators who bring years of industry experience to the classroom. All are leaders in their fields, and all are dedicated to helping you gain knowledge, acquire skills ...