The gemological and spectroscopic characteristics of these type IIa synthetic diamonds suggested that they experienced different growth and/or treatment histories.

In mid-2012, one of the international diamond grading laboratories in Antwerp reported undisclosed CVD synthetic diamonds, causing a stir in the diamond industry.

Recently, an unusual 0.94 ct Fancy yellow-brown emerald cut was submitted to GIA for a synthetic diamond grading report. It contained a cloud of black needle-like inclusions occurring along a plane and showed weak green transmission with fiber-optic illumination.

ジェモロジストによる宝石鑑別を容易にしたGIAの機器開発についての概要

Why and how Shipley created GIA and its mission

Nearly 60 years after the first synthetic diamonds were produced by the General Electric (GE) Corporation, they are making an impact in the jewelry market.

欠陥やスペクトルの特徴のマッピング、色の起源の判定、合成石や処理されたメレーダイヤモンドの鑑別におけるこの技術の有用性を探る。

Explores the fascinating history of natural pearling in Australian waters and examines the properties that might help distinguish these natural pearls from those that are accidentally produced during the culturing process.

A relatively new source of gem-quality turquoise is hosted within slates in Zhushan County of China’s Hubei Province.

新しい鉱床を調査する遠征で、ブルーサファイヤの形態や宝石学的特性が、タンザニアのTunduru（トゥンドゥル）産またはビルマのモゴック産のブルーサファイアに類似することが判明しました。

This article describes the major gem materials of Vietnam, together with their new finds and recent production.

Natural-color saltwater cultured pearls (SWCPs) from Pinctada maxima were studied using UV-Vis-NIR and PL spectroscopy to better understand the mechanisms of their coloration and to separate them from other SWCPs with similar natural colors.