This 7.19-carat alexandrite was cut to feature its beautiful color change. When the light source changes from daylight to incandescent light, the gem’s color changes from bluish green to reddish ...

The majority of saltwater and freshwater pearls bought and sold in the global jewelry markets are “whole pearls,” sometimes referred to as “cyst pearls” (CIBJO, 2017). These pearls form within the ...

This 146.10-carat peridot is in the collection of the Natural History Museum in London Peridot has always been associated with light. In fact, the Egyptians called it the “gem of the sun.” Some ...

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 ...

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 is proud to provide the most comprehensive research in the industry with a world-renowned field gemology team and a dedication to acquiring colored stones directly from the source. Our ...

提到摩根石的名称，就立即令人联想到美丽淡雅的粉红色、紫粉红色和橙粉红色。 - Robert Weldon（罗伯特·韦尔登），Mayer & Watt, Maysville 友情提供，肯塔基州 摩根石作为一种颜色柔和淡雅的宝石而闻名，呈现柔和的粉红色、紫粉红色和橙粉红色。 虽然摩根石通常 ...

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 ...

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.

This ancient necklace dates to 2000BCE. An inscription on the center stone is a South Arabian script from the 8th century BCE. - From "Gems and Gemstones: Timeless Natural Beauty of the Mineral World" ...

Consumers know diamond from the slogan “A Diamond is Forever”. With some care considerations this is relatively true. The Asscher cut was popular decades ago and is again a very popular cut style.

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 ...