At Tiffany, I drifted away from solitaires on platinum toward the sapphire, emerald, and ruby rings in search of something more atypical. Then an avuncular salesperson redirected me back to the diamonds. He cracked a joke every ten seconds, with back-to-back punch lines. I ushered him to the one ring I really liked: a pear-shaped three-stone ring (flawless D color; near-perfect VS1 clarity). I had always grouped pears with other adolescent shapes, like hearts and marquises, but this one was soft and pretty. 727 Fifth Ave., nr. 57th St.; 212-755-8000.