Because they are they long and narrow, marquise diamonds can create the illusion of greater size per carat. This shape also has one of the largest crown surface areas. If you’re looking to maximize the perceived size of a diamond, marquise should be one of your top contenders.
These football shaped stones were originally designed by King Louis XIV of France, fashioned to look like the perfectly shaped mouth of the Marquise of Pompadour. Take a look—what do you think?
The shape of a marquise diamond can be long and narrow or a bit “fat.” The optimal length/width ratios for this cut range from 1.75 to 2.15, with the former being chubbier and the latter looking long and narrow. Symmetry also plays a key role in the appearance of a marquise stone. It is vital to stick with stones that have excellent or very good symmetry because even a slight misalignment in the points can result in an “off” look.
The ‘bow-tie effect’
Marquise diamonds possess some degree of bow‐tie effect, varying from near invisible to severe. This effect cannot be ascertained just by reviewing a diamonds certificate or dimensions‐ only a visual inspection can determine the severity of a bow‐tie.
8 carat marquise diamond ‘cut’ guide
IDEAL | EXCELLENT | VERY GOOD | GOOD | FAIR | POOR | |
|---|---|---|---|---|---|---|
| TABLE % | 55 – 60 | 53 – 63 | 52 or 64 – 65 | 51 or 66 – 68 | 50 or 69 – 70 | < 50 or > 70 |
| DEPTH % | 59 – 63 | 58 – 62 | 56 – 57.9 or 62.1 – 66 | 53 – 55.9 or 66.1 – 71 | 50 – 52.9 or 71.1 – 74 | < 50 or > 74 |
| GIRDLE | Very Thin – Slightly Thick | Very Thin to Thick | Very Thin to Very Thick | Extra Thin to Extra Thick | ||
| CULET | None | Very Small | Small | Medium | > Medium | |
| L/W RATIO | 1.75 – 2.25 | 1.85 – 2.00 | 1.75 – 1.84 or 2.01 – 2.15 | 1.65 – 1.74 or 2.16 – 2.30 | 1.55 – 1.64 or 2.31 – 2.45 | > 1.55 or < 2.45 |
| CROWN HEIGHT % | 12 – 15% | 11.5 – 16.6% | 10.1 – 17.5% | 9 – 18.9% | 7.8 – 19.5% | < 7.8% or > 19.5% |
Marquise diamond ASET and Idealscope images
Both ASET and Idealscope images can help you to better exaluate the light performance of your marquise diamond. Both tools will reveal areas of light leakage in white, but an ASET reading contains more detailed information. Because of this, it is the preferred method for evaluating fancy cut diamonds. However, because of the idealscope’s simplicity, it is a more user-friendly tool for non-gemologists. All you need to know when reading an idealscope is that white areas represent light leakage (bad) and red areas indicate light return (good).
Check out these images below for examples of ASET and Idealscope readings for marquise diamonds:
