Gem-quality rubies and pink to purple sapphires are being recovered from the Luc Yen and Quy Chau mining regions of Vietnam.

In addition to its rich history, the Dresden Green offers an opportunity to gain information about how to distinguish natural from laboratory-irradiated green diamonds.

Today, only by combining different gemological tests with years of practical experience, can a conclusive determination of the origin of a sapphire be made.

This article discusses the history of the Majorica imitation pearl, the manufacturing and marketing processes, and the separation of the Majorica product from its cultured counterparts.

Unusually vivid tourmalines from the state of Paraiba, in north eastern Brazil, have attracted great interest since they first appeared on the international gem market in 1989.

Many deposits of jadeite have been found in Guatemala during the last two decades.

Blue diffusion-treated sapphires are becoming more prevalent than ever before.

During the 1970s and 1980s, treasure hunters discovered the centuries-old remains of the sunken Spanish galleons Nuestra Señora de Atocha and Santa Margarita.

Gem-quality zircon from a relatively underdeveloped locality in the Harts Range of central Australia is described.

One of the most popular exhibits at the Smithsonian Institution, the stunning Fancy Dark grayish blue Hope diamond was formally graded by GIA’s gem laboratory.

The world-renowned Sinkankas collection of books and other publications is now available to the public as part of the Richard T. Liddicoat Gemological Library and Information Center at GIA Santa Monica.

Recent mining at Opal Butte in northeastern Oregon has produced a wide variety of large flawless opals.

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