The Gem Testing Laboratory of Jaipur, India, received for identification an opaque blue specimen, submitted as sapphire.

Deep blue apatite with a cat’s-eye effect, however, is very rare.

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.

The stone owes all of its green color to these shallow radiation stains.

The New York lab encountered another large HPHT-treated diamond that showed stronger pink coloration.

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.

Understanding the color origin of jadeite and reliably determining treatments have become increasingly important in the trade.

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 compilation of gem news from around the world, covering topics such as localities, unusual gem materials, market news, new products, discoveries, jewelry manufacturing techniques, and industry trends.

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

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.

A compilation of gem news from around the world, covering topics such as localities, unusual gem materials, market news, new products, discoveries, jewelry manufacturing techniques, and industry trends.

CVDや伝統的なHPHTダイヤモンド合成法で製造されたものではない、新しい高透明性合成ダイヤモンド材料の予備調査

南アフリカとボツワナの学生は、GIA（米国宝石学会）のジュニア宝石鑑定士プログラムで、宝石学、鉱物学、地質学を学ぶ。