It wouldn’t be spring without a trip to Basel, the Swiss city on the Rhine that hosts 100,000 jewelers and watchmakers every year for the luxury extravaganza known as Baselworld. For those who’ve never been, the fair is, hands down, the most glamorous event on the jewelry calendar.A highlight this year was my appointment with Sevan Biçakçi, the enormously talented Turkish jeweler who has cultivated a global following for his wildly eccentric and technically improbable creations: cocktail rings carved into the likenesses of the Ottoman sultans, gem-encrusted sea creatures, jewels recalling the skyline of his beloved Istanbul.As I admired the newest additions to Sevan’s repertoire, including a rose-cut yellow diamond ring marking his first foray into solitaires, I heard a familiar English accent behind me. I didn’t need to turn around to know it belonged to Theo Fennell, a celebr