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Sapphire
The name “sapphire” can also apply to any corundum that’s not ruby red, another corundum variety.
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Research
Geology of Corundum and Emerald Gem Deposits: A Review
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.
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.
Mineral Inclusions in Ruby and Sapphire from the Bo Welu Gem Deposit in Chanthaburi, Thailand
Identifies mineral inclusions in corundum from this locality for comparison with other global deposits.
Madagascar Sapphire: Low-Temperature Heat Treatment Experiments
Shows how the color of Madagascar sapphire is lightened with heating to relatively low temperatures below 1350°C.
Land of Origins: A Gemological Expedition to Ethiopia
Documents a visit to the sapphire, opal, and emerald mining and trading areas of Ethiopia.
U-Pb Ages of Zircon Inclusions in Sapphires from Ratnapura and Balangoda (Sri Lanka) and Implications for Geographic Origin
Establishes a metamorphic origin for sapphire samples from these deposits, supported by their trace-element composition and inclusion characterization, including the age dating of zircon inclusions.
The Talisman of Charlemagne: New Historical and Gemological Discoveries
Reveals new details about this historical jewel and the results of its first gemological analysis.
Montana Yogo Sapphires’ Unique Gemology
A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.
Large Pargasite Inclusion in Kashmir Sapphire
Unusually large prismatic pargasite inclusions observed in a Kashmir sapphire submitted to the Carlsbad lab for origin determination.
Zircon Cluster in Ethiopian Sapphire
The presence of these zircon clusters might help separate Ethiopian sapphire from other basalt-related sources.
Microscopic Observations of Blue Sapphires Treated with Heat and Pressure
In recent months, sapphires treated under heat and pressure have been documented in the trade.
Update on Trace-Element Chemical Characteristics of Golden Sheen Sapphire
An update the gemological and chemical characteristics of golden sheen sapphires from Kenya.
