Primary and secondary deposits in the Tan Huong–Truc Lau area of northern Vietnam’s Yen Bai Province have supplied rubies and some sapphires for more than a decade.

Since 2002, tsavorite and other grossular varieties have been recovered from a primary deposit at Itrafo, a village in the Andrembesoa area of central Madagascar.

Two-phase inclusions are investigated in alluvial sapphires from deposits in Montana.

Over the last decade, Pakistan has developed into an important source for many gem materials. A number of localities have been identified for emeralds in particular.

Investigating a set of six antique brooches set with diamonds and light blue cabochons.

Gem-quality bright blue to green “Paraíba”-type Cu-bearing tourmaline is now known from deposits in Africa (Nigeria and Mozambique), in addition to three commercial localities in Brazil (in Paraíba and Rio Grande do Norte States).

The Anahí mine in southeastern Bolivia has enjoyed consistent production since 1990 and is best known for its ametrine.

This article, from the Spring 1994 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.

Over the past 15 years a combination of market forces, environmental events, and scientific research has radically changed the cultured pearl industry.

用显微镜评估视觉识别的高温高压处理钻石，观察刻面交接处强烈的荧光。

探究硬玉和绿辉石的区别，以及美国宝石研究院关于这些宝石定义的现行政策。