Designers are rekindling their romance with the stone that the Romans considered the queen of gems for its rainbow range of hues. Opal’s “play of color,” as gemologists call it, is a pattern of iridescent shades or flashes of light that dance across the stone’s surface. It makes the fiery tones in a rare black opal stand out when set in white gold; it transforms a common, milky-white opal into a covetable treasure in rose-gold, diamond-dusted styles. Any way you slice it—cabochon cuts showcase the color best—opals are poised for a renaissance.

1 La D De Dior watch with black opal dial in 18k white gold, palladium, and diamonds; production is limited to five pieces; $56,000; Dior Watches, Springfield, N.J.; 973-467-1890; lvmh.com
2 White opal bracelet with diamonds in 18k rose gold from the Stardust collection; $36,340; Staurino, Valenza, Italy; 39-013 194-3137; staurinofratelli.com
3 Roxanne fire opal stack rings in 24k gold, 1.65 cts. t.w.; $995 each; Yossi Harari, Tel Aviv, Israel; 972-3-6221144; yossiharari.com
4 Necklace in 18k gold with a massive boulder opal center and rose-cut diamond accents; $58,840; Irene Neuwirth, Venice, Calif.; 310-450-6063; ireneneuwirth.com
5 Raw opal ring in 18k gold with tsavorite garnets; $10,710; Kara Ross New York, New York City; 212-223-7272; kararossny.com