图 1：含有一种称作铁方镁石深色内含物的含硼蓝色钻石，作为此项研究的一部分进行了检测。这颗宝石重 0.03 克拉。摄影：Evan M. Smith（埃文·M.·史密斯）。 这是《自然》杂志中发表的文章“来自地球下地幔的含硼蓝色钻石”的延伸摘要。GIA 高级研究员 Evan Smith ...

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 ...

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 ...

This large Australian light opal cabochon weighs 117.85 carats. Small play-of-color flashes of orange and green predominate in a pinfire pattern, with spots of a more muted blue over a grayish ...

Akoya pearls are the small white pearls that most people picture when they think of pearls. They are saltwater pearls, and are usually round and white or cream, with a pink overtone and high luster.

Copper-bearing tourmaline from Mozambique was first recovered in 2001, but its Cu content was not recognized until 2003, and it was not widely sold with its Mozambique origin disclosed until 2005. It ...

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 ...

Since late 2007, rubies and sapphires have been mined by hand methods from both eluvial and primary deposits at Winza in central Tanzania. The gem corundum is related to “dikes” of amphibolitic rocks ...

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 ...

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 ...