It is also called past present and future ring. You can find stones of equal sizes on a three stone ring or one with a slightly larger center stone than the other two side stones. Of course, you can find a three stone engagement ring in many different styles and featuring several gems. Yet again, there is something alluring about choosing diamonds as the three stones. As diamonds can be found in virtually any color of the rainbow and in classic white form, it makes an alluring combination, especially for a three stone ring. You still need to consider which one should be the centerpiece stone and which ones the side stones. If you were thinking about that, consider blue diamond as the showpiece and white variants of the gem on its each side. The allure of a 3 stone blue diamond ring is also second to only the classic white diamond combination.