Signet sees improvements to its web portal as key to competing with new rivals that are capturing market share. These include Blue Nile Inc. and JamesAllen.com, which offers shoppers a virtual ring sizer, 360-degree views of gemstones and an interface for customers to design their own rings.

Competition is also heating up from regional players that have their fingers on the pulse of local communities, Capuano said.

“Jewelry has definitely been tough and millennials are shifting their spending to experience,” said Brian Yarbrough, an analyst at Edward Jones & Co. “That limits your ability to show a lot of growth.”

Signet shares have lost more than a third of their value this year, though they were up less than 1 percent to $60.82 on Friday. Tiffany has fared better, helped by a board shake-up that brought investors optimism that the company could turn things around. Tiffany shares were little changed Friday.

Passion Needed

An additional problem, according to the head of an industry group, is that jewelry sellers have lost a deeper connection with their customers.

“The industry has become so impersonal in many ways. We’ve lost the emotion,” Jean-Marc Lieberherr, CEO of the Diamond Producers Association, said in an interview in New York.

He points to retailers’ efforts to focus shopper attention on certificates that verify a diamond’s quality -- perhaps only slightly more romantic than a low-risk mutual fund. Stores must get clients’ hearts racing, he says, and his group has boosted advertising to help inspire change.

The ads seek to up the drama quotient: One short film that aired at the Academy Awards titled “Runaways” tells an actor’s story of how he eloped with his partner. Another shows a young New York couple getting engaged on camera.

The decline in marriage rates has hurt the industry. Fewer than half of U.S. adults are married today, compared with 72 percent in 1960, according to Pew Research Center.