GIA’s laboratory in Bangkok, Thailand conducts research and provides services such as diamond grading and origin determination, colored stone grading and origin determination and pearl identification ...

Demantoid, green andradite garnet, was discovered in the Central Ural Mountains of Russia in the mid-19th century. A favorite of the Czar's court, demantoid was another victim of the 1917 Bolshevik ...

This article traces the use of pearls from antiquity to the initial appearance of cultured pearls in the 1920s. The first section touches on the early fascination with pearls as revealed through ...

The People's Republic of China has recently placed a high priority on identifying and developing its gemstone resources. Initial exploration by teams of geologists throughout China has identified many ...

Jewellery Arabia is the Middle East’s premier jewellery and watch event. Backed by a 30 year track record of success, this five-day show unites the world’s most desirable brands and extraordinary ...

The Chinese have labored to perfect the art of gemstone carving for several thousand years. Beginning with primitive tools and limited materials, they eventually developed the iron-tipped spindles and ...

Synthetic diamond growth was first documented in 1952 by William Eversole of the Union Carbide Corporation, but it took another two decades before GIA issued the first grading report for a ...

Surface-treated topaz has become a viable alternative to topaz colored by irradiation. Unlike irradiation, which modifies the entire gemstone, coloration by chemical modification is limited to the ...

祖母绿用于首饰已有几个世纪的历史。 有了适当的保养，现代珠宝镶嵌的祖母绿同样可以代代相传。 — Color Masters 友情提供 硬度和韧度 莫氏硬度用以衡量宝石和矿物的硬度。 这些数字基于一 ...

The definition of padparadscha has always been debated. GIA has studied the history of the term and its modern use and indicates on a Colored Stone Identification & Origin Report when a sapphire, in ...

A synthetic gem material is one that is made in a laboratory, but which shares virtually all chemical, optical, and physical characteristics of its natural mineral counterpart, though in some cases, ...

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 ...