When Arun Bohra first laid eyes on this gift’s vivid blue-green stone, he simply had to have it. He acquired it through a prominent diamond dealer, and rather than set it in a traditional diamond ring, the adventurous jeweler created a special backdrop: a playful design inspired by his 3-year-old son’s obsession with snails. The voluminous Nautilus ring ($3.75 million) features the 1.55-carat vivid blue-green diamond amid nearly 8 carats of white diamonds set in 18-karat white gold. Master jewelers in workshops in Rome and Valenza, Italy, produced the piece over a three-month period. “This ring reflects my passion for design and the art of craftsmanship,” says Bohra, whose appointment-only atelier, Arunashi, is located in Beverly Hills, Calif. Always on the hunt for unusual gemstone specimens for his one-of-a-kind pieces, Bohra says some of his clients buy his jewelry as an investment. “Diamonds and gemstones are still the easiest form of portable wealth, and historically they have always gone up in value,” he says. Whether or not the recipient of this gift views the Nautilus as an investment, she will delight in seeing the jeweled snail on her finger.