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Sapphire
The name “sapphire” can also apply to any corundum that’s not ruby red, another corundum variety.
Tools
Mineral Inclusions in Sapphire from Basaltic Terranes in Southern Vietnam: Indicator of Formation Model
Proposes a formation model for sapphire from the main deposits in southern Vietnam based on the chemical composition of their mineral inclusions.
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Low-Temperature Heat Treatment of Pink Sapphires from Ilakaka, Madagascar
Studies the effects of low-temperature heat treatment on inclusions in this gem material, as well as the use of FTIR spectroscopy to detect the treatment.
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A Quantitative Description of the Causes of Color in Corundum
Presents a quantitative means of determining the causes of color in a gem material, using corundum’s six major chromophores as an illustration.
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Article
G&G Announces Most Valuable Article Awards
G&G announces the winners of the Dr. Edward J. Gübelin Most Valuable Article Awards for 2019.
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Article
Coronavirus May Cut Chinese Demand, Diamond Companies See Better Times
The economic impact of the coronavirus in mainland China and Hong Kong. Plus, an update on the diamond market and gold jewelry.
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Geology of Corundum and Emerald Gem Deposits
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.
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A Review of Analytical Methods Used in Geographic Origin Determination of Gemstones
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.
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The Geographic Origin Dilemma
An overview of the geographic origin complexities facing the gem and jewelry industry today.
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Geographic Origin Determination of Blue Sapphire
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.
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Field Gemology: Building a Research Collection and Understanding the Development of Gem Deposits
With more than 90 field expeditions on six continents since 2008, GIA has accumulated over 22,000 colored stone reference samples. This extensive collection of colored stones with known origins supports GIA’s research on geographic origin determination.
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