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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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Tools
Research
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.
Twelve-Rayed Star Sapphire from Thailand
A black star sapphire produced from eastern Thailand, showing both golden and silver rays, is studied at GIA’s Bangkok lab.
Gemstone Guidebook Project
A project coordinated by GIA and the NGO Pact provides a valuable educational tool to women miners in Tanzania.
Gemological Characterization of Sapphires from Yogo Gulch, Montana
A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.
Features of Synthetic Diamonds
Presents a visual guide to the growth processes and major gemological spectroscopic features of synthetic diamonds.
Characterization of Blue Sapphires from the Mogok Stone Tract, Mandalay Region, Burma (Myanmar)
The Mogok Stone Tract of central Myanmar (Burma) is one of the world’s most famed sources of colored stones, particularly ruby, sapphire, and spinel.
Rex Guo: The Science and Art of Recutting Fine Gemstones
Rex Guo describes how he sources and systematically recuts faceted stones to unlock their inner beauty.
Unheated and Unusual Colors
Margit Thorndal of Madagascar Imports offers her perspective on the colored stone market.
