A highly saturated purplish pink to red pezzottaite from a new deposit in Madagascar is encountered in Tucson and tested by GIA researchers.

A chemical and spectroscopic comparison of two purple gem spinel samples, one of them the first reported example of a spinel with a saturated purple color caused predominantly by chromium and cobalt.

With the withdrawal of Soviet troops from Afghanistan, villagers in the Panjshir Valley are turning their attention to the emerald riches of the nearby Hindu Kush Mountains.

Shopping for ruby, the July birthstone? Learn about its history, origins, care and cleaning, and where rubies can be found to help you pick the right one.

With the increasing use of radiation to color enhance gemstones, the issue of radioactivity has become a source of concern for gemologists worldwide.

An examination of the skull-melting technique used to produce cubic zirconia, first introduced in 1976, as well as the market status of this diamond simulant and information about its production and ...

Peer Reviewed Gems & Gemology, Spring 2009, Volume 45, No. 1 Hackmanite/Sodalite from Myanmar and Afghanistan David Kondo and Donna Beaton ...

専門分野で次の段階に進もうとする方も、新しいキャリアを目指す方も、GIA のコースやディプロマプログラムを受講して成功への準備をすることができます。 GIA は、独自の画期的な研究から開発され、業界をリードする ...