Learn how the structure, inclusions and properties of some gemstones interact with light to create unusual visual effects.
Read MoreOpal’s play-of-colour is a lyrical dance: sometimes a grand jeté of bold, broad flashes of colour or smaller, quicksteps of pinpoint flashes.
Read MoreG&G Brief presents an overview of the content of the Winter 2015 issue of Gems & Gemology.
Read MoreAn opal featuring a rare six-rayed star is examined in GIA's Bangkok lab.
Read More“Leopard opal” consists of vesicular basalt impregnated with play-of-colour opal, and is known only from Zimapán, Hidalgo State, Mexico.
Read MoreThis article, from the Winter 2009 issue of Gems & Gemmology, is a compilation of abstracts of important gemmology-related articles published outside of Gems & Gemmology.
Read MoreA simple test easily detected dye treatment in fire opal.
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