Dyed Purple Hydrophane Opal
Opals with an unusual purple bodycolour and strong play-of-colour have recently appeared in the market.
Play-of-colour opal from Wegel Tena, Wollo Province, Ethiopia
A new opal deposit was discovered in 2008 near the village of Wegel Tena, in the volcanic rocks of Ethiopia’s Wollo Province.
Winter 2011 G&G Lab Notes
This section, from the Winter 2011 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
Abstracts; Summer 2009
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.
Gemstone Durability: Design to Display
A treatise on the design, display, care and repair of fine gemstones.
Opal from Querétaro, Mexico: fluid inclusion study
The distinctive orange-to-red “fire" opals from Querétaro have not been found in significant quantities at any other locality.
Green Opal From East Africa
Gemmological and chemical analysis of bright green gem-quality opal from Tanzania.
New occurrence of fire opal from Bemia, Madagascar
Twenty-two gem opals from a new volcanic deposit located near Bemia
Leopard Opal: Play-Of-Colour Opal in Vesicular Basalt from Zimapán, Hidalgo State, Mexico
“Leopard opal” consists of vesicular basalt impregnated with play-of-colour opal, and is known only from Zimapán, Hidalgo State, Mexico.
Opals from Opal Butte, Oregon
Recent mining at Opal Butte in northeastern Oregon has produced a wide variety of large flawless opals.