Blonde and leggy Jessica Emery posed in the window of the new Mervis Diamond Importers store at 17th and K streets NW yesterday clad in sky-high black pumps, a sheer black blouse, a miniskirt and tens of thousands of dollars in bling.

Passersby gaped as she caressed her $8,300 diamond necklace and flashed her $30,000, two-carat, cushion-cut ring. Two white-haired men in suits walked up to the window and stared, laughing. But they were still staring even as they prepared to cross the street.

Emery gave them a little wink.

This is the prime season for jewelry retailers, accounting for about 23 percent of annual sales in 2004, according to a report by consumer research firm Mintel. And the Diamond Information Center said 14 percent of engagements occur around Christmas, the most of any time of the year.

Diamonds have long been associated with engagement -- and romance -- rather than sex and sizzle. Nearly 60 years ago, according to Advertising Age, De Beers coined its now famous slogan, "A diamond is forever." Soon after, 60 percent of married American women had diamond engagement rings, and the gem's sparkle signified long-term commitment.

But as Mervis illustrated yesterday, diamonds are no longer just about vows, as romantic as they may be. Now retailers are trying to broaden their market with advertising campaigns that imbue diamonds with sex appeal.

"It's becoming a more universal market," said Ronnie Mervis, who runs Mervis Diamond.

Men remain the primary buyers of diamonds, and Mervis said he hoped filling his third and newest store with sexy women would persuade them to buy jewelry more often, not just when they are ready to walk down the aisle. Models will be posing in the store windows for the next several weeks, dressed in clothes that represent the "fantasy" of both men and women, Mervis said. There will be lingerie, a high-fashion cocktail dress for a night on the town, even ball gowns.

But no wedding dress.

"Why didn't we do bridal?" Mervis asked one of his employees, Andie Emshoff.

"Because it's not sexy," she responded.

Mervis thought for a moment. "Can we get it sexy?"

Industry leader De Beers, so closely associated with the "forever" campaign, began trying to expand the market two years ago. This time it targeted women.

Sales of diamond rings had grown stagnant in recent years, said Sally Morrison, director of the Diamond Information Center, which represents De Beers. So the company decided to begin pushing non-bridal diamond rings, formerly known as "cocktail rings," for women to wear on their right hands. About 22 percent of the advertising budget of the Diamond Trading Co., De Beers' marketing arm, was spent on the project this year.

"I think for a long time, women felt pretty confident in buying themselves almost anything: a mortgage, a car, an expensive trip. But there was always this taboo about women buying themselves diamond rings," Morrison said. "I think almost deep down that women felt that if they bought themselves a diamond ring, then maybe a man would never buy one for them."

The campaign sought to identify with strong, independent women with slogans such as: "Your left hand says you're taken, your right hand says you can take over." The ads ran in women's magazines such as Elle, InStyle and Vogue. This year, De Beers designated October "Right-Hand Ring Month."

The ads seem to have worked, at least in part. Last year, the company reported sales of fashion diamond rings of $4.2 billion, a 15 percent jump over 2003. Nearly the same amount was spent on diamond engagement rings -- $4.5 billion -- a 5 percent increase. Total sales of diamond jewelry in the United States were $31.5 billion.

Mervis said about 20 percent of his clients are women -- including one attorney who treated herself to a $150,000 "upgrade" of her wedding ring after she won a big case. But the most popular diamond jewelry that women buy for themselves, he said, are diamond stud earrings.

"Every woman desires a pair of studs, one on either side," he quipped.

The catch is that men are still doing the buying.

At the Mervis grand opening yesterday afternoon, only one of the store's six sales booths was occupied by a woman. According to the Diamond Information Center, less than one-third of right-hand rings last year were bought by women. Sixty-nine percent were gifts from men.

"I guess men are responding to our advertising, too," Morrison said.

Outside the Mervis storefront yesterday, coworkers Magden Matin and Drew Belmore, both 23, took a break from their offices at the Corporate Executive Board to examine the offerings in the window -- both the jewels and the models.

Belmore said he liked the display and would probably shop at Mervis if he ever found that special someone.

"They were hot," he said of the models. "A man's man would definitely buy from there."

Here's what a man would think, Matin said laughing:

"My fiancee would look hot in this ring."

Mervis Diamond Importers opens its biggest store on 17th and K streets NW, using models to display its jewelry in a sexier, less traditional fashion.

Model Kristine Kelly of Fairfax adjusts her jewelry before her show at Mervis's newest store.