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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
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.
Preview of Nature Art Science with Paula Crevoshay
Renowned designer Paula Crevoshay discusses artistic influences and her latest creations.
Accurate Reporting of Key Trace Elements in Ruby and Sapphire Using Matrix-Matched Standards
Presents a group of corundum standards developed by GIA to improve the accuracy and efficiency of its laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) instruments.
Two Unusual Natural Sapphires with Synthetic Ruby Overgrowth
For the first time, the Carlsbad and New York labs see natural sapphire seeds with synthetic ruby overgrowth.
An In-Depth Gemological Study of Blue Sapphires from Pailin, Cambodia
A report from GIA Laboratory in Bangkok analyzing 68 blue sapphires from Pailin, Cambodia.
Growth Tube Cluster in Sapphire
Surface-reaching growth tubes in a sapphire provide insight into the gem’s origin and treatment history.
