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Learn how the structure, inclusions and properties of some gemstones interact with light to create unusual visual effects.
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Opal’s play-of-colour is a lyrical dance: sometimes a grand jeté of bold, broad flashes of colour or smaller, quicksteps of pinpoint flashes.
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G&G Brief presents an overview of the content of the Winter 2015 issue of Gems & Gemology.
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An opal featuring a rare six-rayed star is examined in GIA's Bangkok lab.
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This article, from the Summer 2009 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.
Read MoreAn examination of play-of-colour opal from Mexico and its variety of inclusions.
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Matrix opal from Andamooka, in South Australia, is a precious opal-included porous rock that is commonly colour enhanced (carbon impregnated) to imitate the highly prized black opal from Lightning Ridge in northern New South Wales, Australia.
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