The history of Baja California has been closely tied to the exploitation of pearls since the 16th century.

This article presents information about the CVD process, the history of its development, and properties that differentiate the resulting synthetic crystals from natural diamond.

The distinction of natural from cultured pearls traditionally has been based on X-radiography. X-ray computed microtomography (μ-CT) has recently been applied to gain more insight into pearl ...

Malaya garnets from Bekily, Madagascar, are predominantly pink to pinkish orange, with some stones orange to red. Discovered only in the late 1990s, the majority are intermediate members of the pyrope ...

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.

Figure 1. Pleochroism in a 15 ct tanzanite, as seen with the unaided eye through the crown and the pavilion sides and ends. Photo by Wimon Manorotkul. ABSTRACT While virtually all gemological texts ...

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

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.

誕生石「アクアマリン」の意味 & 歴史 アクアマリンの語源はラテン語の「海水」です。古代の船乗りたちには、この宝石が波を落ち着かせ、彼らの海での安全が保たれるのだと言われていました。また、この3月の誕生石は幸せな結婚をもたらすとも考えられていました。ベリル (緑柱石)を身に ...

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 ...