This study investigated the effectiveness of a handheld magnet in detecting synthetic diamonds. A total of 104 synthetic diamonds from nine different manufacturing sources were tested. Of the ...

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 ...

This 5.30-carat emerald from Brazil has a slightly bluish green color. Courtesy John Parrish, courtesy African, Brazilian, Colombian Gems Incorporated. Emerald has many special qualities, but colored ...

GIA studied more than 400 important gemstones from the Gübelin Collection and is committed to sharing this repository of gemological information. This work is a valuable resource for all students, ...

刚玉（红宝石和蓝宝石）呈现出光谱中的各种颜色，从古至今一直是备受欢迎的宝石。摄影：Robert Weldon（罗伯特·韦尔登）/GIA 几千年来，红宝石和蓝宝石（通常为蓝色，有时也有各种其他颜色）一直都是最重要的有色宝石。这些刚玉族矿物包含各种颜色类别 ...

This sapphire from Kashmir has an intense velvety blue color. – Photo: Robert Weldon/GIA. Sapphire is one of the Big three of jewelry colored gemstones—the other two are ruby and emerald. A durable ...

摩根石是为纪念美国金融家和宝石爱好者摩根(J.P. Morgan) 而命名的 摩根 - Corbis 1910 年在马达加斯加新产地发现蔷薇色绿柱石后，George Kunz 于 1910 年 12 月 5 日在纽约科学院会议上提议以摩根石进行命名，以表彰他的朋友和客户摩根(J.P. Morgan)对艺术和科学的经济 ...

Observations of Oval-, Pear-, and Marquise-Shaped Diamonds: Implications for Fancy Cut Grading Presents findings from observations of oval-, pear-, and marquise-shaped diamonds, laying the groundwork ...

Figure 1. A pink 173.22 ct fluorite, measuring 35 × 33 mm, from Uri, Switzerland. This stone is representative of minerals discovered by strahlers, mineral hunters from the Swiss Alps. Photo by Kevin ...

GIA Instruments works hand-in-hand with GIA’s laboratory, education and research teams, as well as the jewelry trade to develop the instrumentation you need to prepare you for the challenges of ...

Figure 1. The ten cabochon-cut gems examined are shown alongside the valves of C. virginica (Eastern or American oyster). The interior and exterior valves shown belong to one oyster. Photo by Diego ...

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, ...