Sharon Bohannon, November 11, 2016
Learn how the structure, inclusions and properties of some gemstones interact with light to create unusual visual effects.
Read MoreSharon Bohannon, September 20, 2019
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.
Read MoreRussell Shor, February 1, 2016
G&G Brief presents an overview of the content of the Winter 2015 issue of Gems & Gemology.
Read MoreWasura Soonthorntantikul, June 27, 2014
An opal featuring a rare six-rayed star is examined in GIA's Bangkok lab.
Read MoreBrendan M. Laurs, Thomas W. Overton
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 MoreJohn I. Koivula, Chuck Fryer, June 1, 1983
An examination of play-of-colour opal from Mexico and its variety of inclusions.
Read MoreGrahame Brown, June 1, 1991
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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