The September birthstone is sapphire – a gem that’s been cherished for thousands of years. Although the term sapphire usually refers to the blue variety of corundum (ruby is the red variety), this ...

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 ...

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 ...

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 ...

莫氏硬度用以衡量宝石和矿物的硬度。 这些数值基于一种矿物可被其他物品划伤的相对难易程度得出。 但莫氏硬度易产生误导。 矿物之间的等级差距并不相等。 举例来说，钻石仅比刚玉高一个 ...

GIA’s D-to-Z color grading system is based on the relative absence of color. GIA’s Fancy colored diamond color grading is based on the presence of color. GIA describes color in terms of hue (the color ...

业内称为帝王拓帕石的宝石拥有非常珍贵的颜色，也非常罕见。 不同颜色的拓帕石其价值要素具有微妙差异。 帝王色、蓝色和黄色需根据相应的标准进行评估。 寻找珠宝商 使用邮政编码寻找您 ...