Intel, the once-dominant chip manufacturer, was still a member of the blue chip Dow Jones Industrial Average a couple of months ago. As Jinjoo Lee writes for Heard on the Street's weekend essay, companies that mine, polish or sell the gems are scrambling to distinguish the natural versions and hold up their price even as mere mortals can't tell the difference between them and man-made ones. Heard's Jonathan Weil points out a distinction that many software companies have used, and often abused—the so-called Rule of 40.