The October issue of Elle announced Tiffany & Co.'s new square diamond cut, which the magazine says Tiffany is patenting. It's been a hundred years since Tiffany introduced its classic six-prong setting for round stones, so it's time for a new angle, so to speak. Tiffany has been advertising the style as well in its cherished third-page slot in The New York Times. The retailer's widespread and ever-expanding advertising should add fuel to the firestorm of interest in the geometry of diamonds.

- by Peggy Jo Donahue