opal

Mosaic opal. Photo by Mauro Cateb. Licensed under CC By 2.0.

Crystal opal set in 22k gold, with 24k granule accents and pierced sterling silver base with overlay. Jewelry and photo by Jessa and Mark Anderson.…

Matrix opal. Photo by John Hritz. Licensed under CC By 2.0.

Opal triplet, made of Australian rough, a ceramic base, and a quartz top (30 x 23 mm).

“Harlequin Prince” black opal, 215.85 cts, Lightning Ridge, American Museum of Natural History. Photo by greyloch. Licensed under…

This black opal shows a wide range of colors. Stayish Mine, Wollo Province, Ethiopia. Photo by James St. John. Licensed under CC By 2.0.

Peruvian opal wire-wrapped ring with brass band. Photo by Zoe. Licensed under CC By 2.0.

This 15.5-carat double cabochon opal has a flash of color across its entire face. Tsehay Mewcha, Wollo, Welo Province, Ethiopia. © Rob Lavinsky,…

Diamond and gold pendant with 19.9-ct Ethiopian Welo opal. Photo by Dpulitzer. Licensed under CC By-SA 4.0.