Although not as popular as the classic round cut, the marquise diamond cut is a good choice if you want a stone that is more elongated. This cut is especially suitable for rings as it can underscore the length of your fingers. Let’s take a look at how you should evaluate the quality of a marquise-cut diamond when choosing such a stone.
What Is Marquise Cut?
Marquise cut is a brilliant diamond cut shaped like an ellipse. The most distinctive feature of this cut is that two of its ends are pointed and sharp.
Compared with the round cut, the marquise cut is longer and narrower.
This characteristic makes a marquise-cut stone look larger in a face-up position than a round-cut diamond of the same carat.
Selecting Color for a Marquise Diamond
Compared with other brilliant cuts, the marquise cut tends to make a diamond’s color more visible.
This is why it is recommended that you do not buy a stone with a color grade lower than G or H if you don’t want your diamond to have a visible yellowish tint.
However, if the stone is going to be set in yellow gold, I or J color may work just fine, as any yellow coloring will blend with the setting, making the white in the diamond stand out.
Choosing Clarity for a Marquise Diamond
Inclusions in marquise-cut diamonds tend to be more visible than in round diamonds, all else being equal.
The most cost-effective approach to selecting clarity would be to choose a stone that has a clarity grade that is as low as possible while still having few or no inclusions visible with the naked eye.
(Most inclusions that graders base their clarity assessment on can only be seen with a microscope anyway.)
When selecting a marquise stone, make sure that there are no visible inclusions towards the center of the diamond. Inclusions that are closer to the stone’s edges can be more easily hidden by a setting.
If you focus your search on marquise diamonds of clarity in the VS/SI range, you may easily find a stone that looks clean to the naked eye.
It is not recommended that you go below SI2 clarity, however, as stones in the I-clarity range usually have easily visible inclusions, some of which are also centrally located.
Marquise Cut Proportions
Ideal proportions for the marquise cut are not as precisely established as those for the round cut, but here are some approximate guidelines that can help you make a choice:
Table: The length of the table (the top) of the diamond should ideally be 53% to 63% of the length of its girdle (the stone’s outermost edge). Avoid stones whose table percentage is lower than 50% or higher than 70%.
Crown height: The height of the crown (the upper portion of the stone, above the girdle) should be 10-17% of the girdle, ideally in the 12-15% range. Diamonds whose crown heights are greater than 20% or lower than 8% are not desirable.
Depth: Ideally, the total depth of the stone (the distance from its top to its bottom) should be 59-63% of the girdle. Values higher than 70% or lower than 50% are not as desirable.
Girdle: Look for stones with girdles whose size ranges from thin to thick. Avoid marquise diamonds with extremely thin girdles as they are at high risk of chipping.
Extremely thick girdles are also undesirable as they make a diamond look somewhat disproportional.
Length-to-width ratio: The ideal length for a marquise-cut diamond is 1.75 to 2.25 of its width; in other words, the stone should be about twice as longs as it is wide.
Although this parameter comes down to personal choice, very thin stones can have overly thin pointed ends, which could break easily.
Symmetry: Make sure that the diamond has very good symmetry at the very least. This means that the pointed ends of the stone should be aligned and its left side should be symmetrical to the right one.
If there is asymmetry, it will be very visible once the diamond is set in a mounting.
Bowtie effect: This refers to the dark spot that is formed at the center of a marquise diamond when you look at it from the top. The effect results from the way the stone returns light and is a sign of a well-cut stone.
If you cannot see such a dark area in the diamond’s center when the stone is in a face-up position, then the marquise cut is likely too deep or too shallow.
Settings and Marquise Cut
It is highly recommended that a marquise diamond be mounted in a setting that protects the stone’s vulnerable pointed ends.
These parts can easily be chipped if hit, not to mention that it is not safe to wear a diamond with sharp ends that are not covered.
One of the most suitable settings for this type of cut is the V-prong setting, which wraps the sharp edges of a stone in metal and protects them.