A marquise diamond gives you two points to work with. Set along the finger, they draw the eye toward the knuckle and fingertip. The outline can feel quite different from one ring to the next. If you have two favorites, start by putting their top views side by side at the same scale.
Compare width as well as length
Look for the length and width in millimeters. A 10 × 5 mm stone has a length-to-width ratio of 2.00. A 10 × 5.5 mm stone is about 1.82 and has a fuller outline at the same length. Use those numbers to decide which silhouette you prefer and how much room the stone will take up on your finger.
Next, imagine a line joining the two tips. Do the sides curve out by a similar amount? Is the widest part roughly centered? A straight-on image makes it easier to see whether one shoulder looks fuller or whether a tip appears off-center. Check a second angle if the ring was tilted in the first photo.
Watch the center as the ring turns
Some marquise diamonds show a dark band across the middle known as a bow tie. If you have a video, watch it through a slow tilt and note how much of the stone stays dark as the angle changes. Diffuse daylight and ordinary indoor light can give you a better idea of what you will see most days. GIA’s guide to choosing a marquise diamond explains what to look for in the outline, reflections, and setting.
Check how the setting covers both tips
Ask for a close-up of both points. A V-prong wraps around the tip and can help protect it from knocks. A bezel can cover more of the edge, so compare how much of the pointed outline you can see from above. From the side, note how high the diamond sits and where the tips end relative to the band.
For a final comparison, keep the metal color the same and switch the band. The straight solitaire above leaves a clear outline around both points. The twisted band brings curved lines into the shoulders. Look at the two together and decide which detail you want to notice first when you glance at your hand.