When DeBeers debuted its right-hand diamond rings last summer with a relatively modest print campaign, the sparklers became an instant hit. Halle Berry, Cameron Diaz and Sarah Jessica Parker all wore them, while Katie Couric sported hers when she featured them on the Today show. As experts buzzed about women's disposable income and girl-power advertising, Wal-Mart hastily introduced a selection starting at $177, with solid sales results.
Apparently diamonds are not only forever; they're for everyone, all the time. That raises a question: If diamonds have gone mass market, what about glamour, that mysterious quality that used to cling to the...