When Zendaya appeared on the 2025 Golden Globes red carpet with a diamond engagement ring on her hand, the world took notice. Given her years as a Bvlgari ambassador, the design didn’t seem quite like something you’d find at the Italian luxury label. Instead, the actress went down an independent route. The designer behind that five carat, cushion cut creation? Jessica McCormack , a London-based jeweler who has become a favorite among Hollywood stars and downtown cool girls alike. With the likes of Emma Stone, Margot Robbie , and Zoe Kravitz (who has also fronted campaigns for McCormack) as fans, the brand is giving a modern, youthful spin on diamonds. Working in jewelry seemed to be inevitable for McCormack. Growing up in New Zealand, her father was an auctioneer and as a result, she was exposed to art and antiques from an early age. At 25 she moved to London, where a stint at Sotheby’s honed her knowledge of gems and metalworking.…