Not all engagement rings are created equal — and when it comes to choosing the ring, the diamond cut matters just as much as the carat size. The cut determines how a ring sparkles, how it looks on the ...

Call it the “Swift Effect,” but the antique style is poised for a revival.

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 ...