
Silvery Rutile “Tufts” in Quartz
Get Your New GIA Alumni Association Logo and Support Materials
Alumni across the globe participate in chapter events and are out in full force to support the trade. There are a variety of ways you can join them.


Multi-Color-Zoned Quartz from Brazil
A Brazilian quartz with unusual color zoning caused by variable iron content is examined.

Yellow, Green, and Blue Sapphires Reportedly from Antang and Gombe, Nigeria
Nineteen sapphires of various colors, reportedly from sources in northern Nigeria, are studied in GIA’s Tokyo laboratory.

Synthetic Diamond Fraudulently Inscribed To Match Natural Diamond Report
A specimen seen in the Carlsbad lab for an updated diamond grading report does not match the previous documentation.



メレー:現代デザインの構成要素
ジュエリーデザインにおいてメレーがいかに多用性があるか、そしてGIAの品質保証のベンチマークを利用して、長持ちするジュエリーをデザインし製造する方法について説明します。


大きなダイヤモンド、その意外な起源
博士号取得後、GIAで研究科学者を務めるEvan Smith博士は、稀少なダイヤモンドで発見されるインクルージョンの特性を系統的に表す研究に従事しています。 2017年度JCKラスベガスショーで録画されたこのビデオのプレゼンテーションでは、Smith博士が大きなダイヤモンドの意外な起源およびその特徴から地球に関して学べることについて報告します。

合成ダイヤモンドの最新事情
Dr. James Shigley, GIA distinguished research fellow, is one of the foremost experts in diamonds and their identification. In this presentation recorded at the 2017 JCK Las Vegas show, he shares the latest developments about HPHT and CVD synthetic diamond

コロンビアのエメラルド産業: 変化の風
GIAでフィールドジェモロジィの教育マネージャーを務めるAndy Lucasが、コロンビアの主要なエメラルド鉱山や切削作業が行われる現場で観察した変化について発表します。



Characterization of Mg and Fe Contents in Nephrite Using Raman Spectroscopy
Evaluates the usefulness of Raman spectroscopy in distinguishing the color varieties of nephrite based on the relative ratio of Mg to Fe concentration.

An Update on Tourmaline from Luc Yen, Vietnam
Reviews the characteristics of tourmaline from pegmatites in the Luc Yen district of northern Vietnam.

Geology and Development of the Lomonosov Deposit, Northwestern Russia
Reviews diamond discoveries at the Lomonosov deposit, as well as the geology of the Arkhangelsk kimberlite province.

Carbonado Diamond: A Review of Properties and Origin
Presents a detailed examination of about 800 samples of carbonado diamond from Brazil and the Central African Republic, including possible models for its genesis.


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