Synthetic emeralds grown hydrothermally in an alkali-free, chlorine-bearing solution have been manufactured in Guilin, China, since 1987. Diagnostic microscopic features include growth and color ...

A look at the history of analytical instruments used for gem testing. UV-Vis-NIR spectroscopy measures how gemstones absorb and interact with light across the ultraviolet, visible, and near-infrared ...

Following up on Nassau's 1981 article on the technical aspects of heat treating ruby and sapphire, the author reports his personal observations of the actual heat treatment process in Bangkok. He ...

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 ...

Knowledge of the durability of a gemstone is critical to understanding the risks involved in the various setting, repair, and cleaning procedures commonly used by the jeweler. Some gemstones need ...

The first substantiated identification of corundum (var. ruby) occurring as an inclusion in natural diamond is presented. The ruby is assigned to the eclogitic suite of inclusions in diamond, and the ...

Since Robert Crowningshield's discovery in the late 1950s that diamonds that have been artificially colored by irradiation and subsequent annealing could be identified by their characteristic ...

Although the Art Deco period extends roughly from 1910 to well into the 1930s, it was primarily a product of the "Roaring '20s." This was a wonderfully decadent era. It was an age of Prohibition and ...

丹泉石可能呈现浓郁而深邃的紫蓝色。 丹泉石是紫蓝色到蓝紫色的矿物黝帘石类别。世界上只有一个地区以商业规模开采丹泉石：坦桑尼亚（英文为 Tanzania）的 Merelani（梅勒拉尼）山，该宝石也 ...

位于 GIA 全球总部的 The Robert Mouawad Campus（罗伯特·懋琬校区）是首屈一指的宝石研究和珠宝设计学校，将现代教室以及国际公认的博物馆充分整合于加利福尼亚州美丽的卡尔斯巴德。 GIA 纽约 ...

Chatham, Knischka, and Lechleitner, as well as other manufacturers, are known to have treated Verneuil flame-fusion synthetic rubies by immersion in a flux melt to induce patterns like the ...

The GIA Colored Diamond Grading Report includes a full quality assessment of a colored diamond including the color grade and color origin (natural or treated), carat weight, and clarity along with a ...