Consumers now, more than ever, have a heightened awareness of sustainably and ethically sourced products. The GIA Diamond Origin Report uses scientific evaluation to provide confirmation of a ...

3月の2つの誕生石であるアクアマリンとブラッドストーンは全く異なって見えますが、幸福をもたらすという共通の効果を持っています。アクアマリンの誕生石からは海の色が思い浮かびます。深みのあるグリーンブルーから明るめのわずかに緑がかった ...

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 ...

Metrology, the science of measurement and its application, plays a critical role in the accuracy of GIA’s research and laboratory services. The metrology team closely monitors the performance of ...

With decades of expertise and laboratory locations worldwide, GIA uses more advanced instrumentation that extends far beyond the boundaries of standard gemological testing. The comprehensive analysis ...

Jade is one of the most misunderstood gemstones. It is actually two separate materials: jadeite and nephrite. Together, these materials have more simulants than most other gems. Thus, it is important ...

Figure 1. This alexandrite cabochon appears brownish green in fluorescent light (left) and brownish purple in incandescent light (right). The cabochon shows chatoyancy under both forms of illumination ...

Pietersite has been described as a brecciated variety of tiger’s-eye. This study examined pietersite specimens from Namibia and China (the main sources) using powder X-ray diffraction, optical ...

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 ...

加利福尼亚州卡尔斯巴德 – 2025 年 1 月 29 日 – GIA 实地宝石学家最近完成了第 100 次考察，进一步丰富了研究院从世界各地彩色宝石开采地收集而来的独立验证宝石学信息。 在此次前往肯尼亚和坦桑尼亚的考察中，GIA 团队收集了大量的沙弗莱石、尖晶石和蓝 ...

CARLSBAD, Calif. – January 29, 2025 – GIA field gemologists recently completed their one-hundredth expedition, adding to the Institute’s unrivaled store of independently verified gemological ...