Cut
Ideally, the
marquise-cut diamond has a length that is 1.75 to 2.25 times its width. That means somewhere around twice as long, so keep this in mind when browsing
stones at the jeweler. What you choose will radically affect the final look of the
ring on your finger.
Color
Marquise diamonds generally show off their
color, so prefer something at grade I or higher. This level is warmer, but face-up, it has a white appearance.
Clarity
The best
clarity grade you can get for the
marquise cut is
SI2, which is plenty for a good-looking
stone. This sufficiently hides most imperfections and is more effective at this than most other
shapes. The
brilliant-cut obscures most of the inner details unless one takes a long, close look, which is unlikely in most
settings. That said, you could try to get a higher
clarity grade after making sure it fits in your budget.