From top: Temple St. Clair’s 18k yellow gold, aquamarine, moonstone, sapphire and diamond cuff, $70,000, 800.590.7985,; Martin Katz’s 18k white gold, moonstone and diamond ring, $65,000, at Martin Katz, Beverly Hills and New York, 866.956.7200,; Gioia’s 18k white gold, moonstone and diamond brooch, $185,000, at Gioia, New York, 212.223.3146; Tiffany & Co.’s platinum, moonstone and sapphire medallion necklace, $100,000, at Tiffany & Co., 800.526.0649.

Possessing a quiet mystery, moonstones are decidedly spiri-tual gems. In India, the luminous rocks are thought to provoke vivid dreams, while Arabic women are known to sew them into their clothes for good luck. There are, of course, more immediate ways to grasp a piece of their magic. Take Gioia’s iridescent brooch, twinkling with diamonds that sway gently, evoking the undulations of a jellyfish, or Tiffany’s large cabochon stone, fashioned into a pendant and modeled after a pin that Louis Comfort Tiffany designed in the early 20th century. Temple St. Clair’s cluster cuff features a bright, watery combination of moonstones and aquamarine, while Martin Katz’s whimsical ring, its stone set among 480 tiny diamonds, will surely stir nighttime reveries.