◂ BACK TO GEM ENCYCLOPEDIA
Opal
Fireworks. Jellyfish. Galaxies. Lightning. Opal's shifting play of kaleidoscopic colors is unlike any other gem.
See Gem As
Tools
Research
Opals from Opal Butte, Oregon
Recent mining at Opal Butte in northeastern Oregon has produced a wide variety of large flawless opals.
Gemstone Durability: Design to Display
A treatise on the design, display, care and repair of fine gemstones.
Summer 1986 G&G Lab Notes
This section, from the Summer 1986 issue of Gems & Gemology, is a compilation of interesting finds from GIA’s laboratories.
Opal Description
Opal is known for its unique display of flashing rainbow colors called play-of-color. There are two broad classes of opal: precious and common. Precious opal displays play-of-color, common opal does not.
Opal History and Lore
Writers have compared opals to volcanoes, galaxies, and fireworks. Admirers gave extraordinary opals poetic names like Pandora, Light of the World, and Empress.
Opal Care and Cleaning Guide
Learn about opal's durability and how to care for your opal jewelry.
Opal Quality Factors
Individual opals are as diverse as snowflakes or fingerprints and can vary widely in appearance and quality. Learn about the factors that make opals so desirable!
Abstracts; Winter 1991
This article, from the Winter 1991 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.
Snowflakes in Opal
Winter 2011 G&G Lab Notes
This section, from the Winter 2011 issue of Gems & Gemology, is a compilation of interesting finds from GIA’s laboratories.
Chrysoprase and Prase Opal from Haneti, Central Tanzania
Commercial quantities of gem-quality chrysoprase and green prase opal (nickel-bearing chalcedony and common opal, respectively) have been recovered from altered serpentinite deposits near Haneti, Tanzania.
