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Geographic Origin Determination of Blue Sapphire (英語)

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 Ruby (英語)

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.

野外宝石学：研究用標本コレクションの構築と宝石鉱床の形成過程の理解

January 31, 2020

GIAは2008年以来、6大陸で90回以上の現地調査を実施し、22,000点を超えるカラーストーンの参照サンプルを収集してきました。産地が判明しているこの膨大なカラーストーンコレクションは、GIAの産地特定に関する研究を支えています。

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.

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

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.

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.

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.

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.