BUILDING A MYSTERY: Even though fashion week is really all about ready-to-wear, Van Cleef & Arpels president and chief executive officer Stanislas de Quercize has a trick up his sleeve that should garner a fair share of the limelight. At an exclusive press luncheon Friday at Country, he and Lutz Bethge, managing director of Montblanc — both Compagnie Financière Richemont AG-owned firms celebrated their centennials in 2006 — will unveil Mystery Masterpiece, three limited-edition jeweled writing instruments valued at $730,000 each. The pens come with rubies, emeralds or sapphires in Van Cleef's signature Mystery Setting and are topped with a Montblanc star made of round diamonds. Three of each style will be produced. "We are so excited to show the pens for the first time," said de Quercize. "It's a tribute to craftsmanship. It took more than 800 diamonds and over 18 months to create." Though there are many pen collectors out there, one possible buyer for one of the rare nine pens could be author Linda Fairstein, the former New York prosecutor who purchases a Montblanc pen every time she finishes a book. In fact, last month Montblanc feted her latest tome, "Bad Blood," and, of course, Fairstein took a gander around the store. "I love [writing with a] pen and paper, and I love to write notes," she said. Fairstein also recently submitted her latest manuscript. Get ready, de Quercize.

MADE BY JADE: Designing a limited edition T-shirt to benefit the Climate Project was a snap for Jade Jagger. During Tuesday night's kickoff party for the campaign, which includes Ts by Kate Moss, Gwyneth Paltrow, Diane von Furstenberg and other celebs, Moss literally signed off on her design with "Kate was here" written across the back hem of the shirt.

Jagger said her Jezebel clothing collection will make its debut at a yet-to-be-determined store in September. A few items from the collection are already being sold in Ibiza, her favorite island getaway. Isetan's Tokyo store will have the first Jezebel concept shop. Whatever the endeavor, the designer pretty much goes with her gut. "I never listen to any advice. Listen to yourself, I say. You've got everything within."