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Geographic Origin Determination of Blue Sapphire (英语)

January 31, 2020

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.

Geographic Origin Determination of Alexandrite

January 31, 2020

The geographic source of this rare color-change gem has a significant impact on value. Trace element chemistry profiles allow GIA to accurately determine origin for alexandrite from several countries.

野外宝石学：建立研究收藏并了解宝石矿床的形成

January 31, 2020

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。

Geographic Origin Determination of Ruby (英语)

January 31, 2020

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.

Geographic Origin Determination of Paraíba Tourmaline

January 31, 2020

Copper-bearing gem tourmaline, known as Paraíba tourmaline after the location of its original discovery, is prized for its vivid blue to green color. This article explains GIA’s use of quantitative chemical analyses to distinguish samples from Brazil, Nigeria, and Mozambique.

A Review of Analytical Methods Used in Geographic Origin Determination of Gemstones (英语)

January 31, 2020

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.

Geology of Corundum and Emerald Gem Deposits: A Review

January 31, 2020

Over the last two decades, knowledge of the formation of gem deposits has improved significantly. This article reviews the state of our knowledge of the geology and genesis of gem corundum and emerald deposits.

Geographic Origin Determination of Emerald

January 31, 2020

The relative chemical diversity of emeralds from different deposits worldwide allows clear origin determination in most cases. This contribution explains the criteria used by GIA to make geographic origin conclusions for emeralds.