GIA 与北大资源研修学院 (Peking University Resource College) 开展合作办学项目，在深圳提供校园课程、实习班和学生工作室。这些课程由 GIA 老师用中文授课。 除非另有说明，所有课程均用中文授课。 2024 年课程时间表 开课日期并不包括新生报到日 。 如需了解关于 ...

Fine-color, large, and eye-clean (lacking visible inclusions) rubies like this 11.01carat (ct) stone from Myanmar (formerly known as Burma) are extremely rare and valuable. – Photo: Robert Weldon/GIA.

Opal can range from 5 to 6.5 on the Mohs hardness scale. Hardness and toughness Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or difficulty with ...

Most diamonds used in jewelry range from colorless to light yellow and are graded on a scale from D (colorless) to Z (light yellow). Those with less color, or closer to colorless, are generally more ...

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, ...

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 ...

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 American Chemical Society’s (ACS) Committee on Chemical Safety (CCS) promotes and facilitates safe practices in chemical activities and provides guidance for academic institutions. Such guidance ...

In an effort to help you understand the GIA Cut Grading System more fully, and to make the best use of it in your business, we provide these informative charts and booklets that summarize the system, ...

The GIA Diamond Grading Report includes an assessment of the 4Cs – Color, Clarity, Cut, and Carat Weight – along with a plotted diagram of its clarity characteristics and a graphic representation of ...

This 10.12 ct Fancy Vivid yellow pear shape illustrates the effect a fancy shape can have on intensifying the color in a yellow diamond. - Courtesy the Scarselli Family Color In diamonds, rarity ...

Due to the overwhelming popularity of GIA’s limited time, no-charge offer, all GIA Essentials classes starting in May and June – the period of the offer – are full. The offer is closed and we cannot ...