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The name “sapphire” can also apply to any corundum that’s not ruby red, another corundum variety.

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Madagascar Beauty

This 7.04-ct. oval sapphire is from a new source, the island Madagascar.

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Blue Velvet

Deep, intense, velvety blue describes this sapphire’s color.

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Best in Daylight

Blue sapphire looks best in daylight and fluorescent light.

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Spindle Shape

This spindle-shaped crystal from Sri Lanka weighs 70.10-cts.

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Color Zoning

Blue color distribution in sapphire crystals is often uneven.

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There is a second sapphire crystal growing into the larger one.

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High-quality sapphires from southern Vietnam set in rings
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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Treated pink sapphires from Ilakaka, Madagascar
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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Gem corundum colored by a single chromophore
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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Two blue sapphires side-by-side
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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A large group of people in a hallway.
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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Sapphire crystal from Kataragama, Sri Lanka
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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Confocal Raman spectroscopy
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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Gemstone classics from sources old and new
The Geographic Origin Dilemma

An overview of the geographic origin complexities facing the gem and jewelry industry today.

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Matched pair of Kashmir sapphires
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 gemologists sort through gem gravel in Myanmar
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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