opal

Boulder opal rough, thin opal layer attached to original matrix, 6 cm in length. Photo by Hannes Grobe. Licensed under CC By-SA 2.5.

Crystal opal ring, 8 cts. © Urth Kandi Jewelry. Used with permission.

This polished 19.25-ct Australian black opal shows the cracks known as “crazing.” © Opal Auctions. Used with permission.

People have prized opals and their play of colors for millennia. Pliny the Elder described opals as “made up of the glories of the most precious…

20.05-ct Ethiopian Welo opal, set in 14k gold and surrounded by diamonds. Photo by Doxymo. Licensed under CC By-SA 4.0.

1.30-ct faceted common opal. Photo © Joel E. Arem, PhD, FGA. Used with permission.

Black opals have a black or deep blue body color and show play of color, too. Gold bracelet with 9-ct black opal, on display at the Cleveland Museum…

Opal ring, Slovakia. Photo by Slovakiaopal. Licensed under CC By-SA 4.0.

Protective settings can help keep opals safe from scratches and impacts. Men’s ring with 10.70-ct opal. Photo by Dan Mekis, Red Carpet Opals.…