High-end jewelers have a problem. Millennials aren’t into the sparkly, special-occasion pieces that dazzled their parents and grandparents decades ago.
To catch on with twenty- and thirty-somethings, Bulgari, De Beers and others are rethinking store design, launching edgier, lower-priced collections and enlisting millennial favorites such as actress Elle Fanning and models Bella Hadid and Lily Aldridge to promote them.
Jewelers...