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A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.
Read MorePresents 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.
Read MoreThe heat treatment of corundum involving lattice diffusion of beryllium (Be) at temperatures over 1800°C has become a major issue in the gem trade.
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Gem-quality rubies and pink to purple sapphires are being recovered from the Luc Yen and Quy Chau mining regions of Vietnam.
Read MoreAn overview of the potential effects that heat treatment can have on corundum.
Read MoreThe authors determined that there are actually seven types of "yellow" sapphire on the market today, which differ in the cause of colour and the stability of the colour to light.
Read MoreMost Russian hydrothermal synthetic rubies and pink, orange, green, blue and violet sapphires—coloured by chromium and/or nickel—reveal diagnostic zigzag or mosaic-like growth structures associated with colour zoning.
Read MoreBlue sapphires from China are similar to gem corundum from Australia, Thailand, and Kampuchea (Camodia).
Read MoreGreater amounts of colourless sapphire—promoted primarily as diamond substitutes, but also as natural gemstones—have been seen in the gem market during the past decade.
Read MoreGem-quality rubies and fancy-colour sapphires have been recovered from dolomite marble lenses located high in the Himalayan mountains of east-central Nepal (Ganesh Himal).
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