Research Article Search Results

A newly found deposit of sapphire in Madagascar is explored.

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

Northern Vietnam began producing significant quantities of rubies and fancy sapphires in the late 1980s.

Examination of a 0.40 ct near-colorless round brilliant diamond with a large inclusion resembling a dumbbell

A new opal deposit was discovered in 2008 near the village of Wegel Tena, in volcanic rocks of Ethiopia’s Wollo Province.

A group of large, high-quality CVD material demonstrates the continued challenge of identifying laboratory-grown gems.

Progress in creating laboratory-grown CVD diamonds allows for larger sizes, including the largest yet seen at the Carlsbad lab.

Geographic origin determination relies on a combination of gemological observations and advanced analytical tools. This contribution reviews the analytical methods commonly used to establish origin.

In some cases, the value of a sapphire depends strongly on its geographic origin. This article details the origin data GIA has collected for blue sapphire and describes its methodology for using the data in geographic origin determination.

The world ruby market has undergone dramatic change in recent years, especially with the development of ruby mining in Mozambique. This contribution outlines GIA’s methods and criteria for establishing the geographic origin of ruby.

自2008年以来，GIA已在六大洲开展了90多次实地考察，积累了超过22,000件彩色宝石参考样品。这些来源明确的彩色宝石藏品为GIA的地理产地鉴定研究提供了有力支持。