DIAMOND POINT — Family, friends and chocolate were on Joan Butler’s planner as she marked a century on earth. Butler’s garage was decked out with balloons, photographs and smiling people on Dec. 19.
Last fall, the jewelry designer Kindred Lubeck took an elevator up six floors to a high-end showroom in New York’s diamond district. She was buzzed inside a fluorescent-lit vestibule, then waited; the ...