The Marquise Cut Diamond

All about this brilliant-cut stone.

Legend has it that the shape of marquise-cut engagement rings comes from the smile of Jeanne Antoinette Poisson, Marquise of Pompadour, an influential member of the court of Louis XV, king of France. The king requested that the state jewelers cut a brilliant stone to match the shape of her lips. The fashion caught on and the marquise cut, named after the noble rank which lies between that of the duke and the baron, became a symbol of wealth and rank among the nobility.

Diamond Cut

The modern cut of the marquise is in all likelihood substantially different to original as modern knowledge regarding the manner in which light travels through diamonds and is reflected off surfaces has been utilised to make the marquise one of the “brilliant” cuts, meaning that the angles between the surfaces of the stone have been optimised to reflect as much light as possible, offering a brilliant sparkle. Despite this, it can be one of the most difficult shapes of diamond to buy due to the huge variations in the diamonds that are available and a large number of poor quality stones.

Diamonds that aren’t cut in the traditional round shape are known as “fancy” shapes, and they are all considerably less expensive than a round, brilliant-cut stone. The marquise is one of the fanciest of all, with its brilliant facets cut into an elegant shape, but it’s also one of the most competitively priced diamond cuts.


Marquise Diamond Size

The ideal proportions for a marquise diamond are shallow and wide.

Some diamond shapes need to be cut much deeper in order to bounce the light off internal surfaces in the correct way, which means that a lot of the weight of the stone is in the bottom half, where it can’t be seen once it’s in a ring setting.

But due to the fact that the marquise is shallow, it has a larger surface area, and thus actually looks considerably bigger than most other shapes.

The picture is a scale diagram of a 1 carat round brilliant diamond and a 1-carat marquise – you can see that the marquise looks substantially bigger, even though it weighs the same.


Another advantage of the marquise shape is that it has a flattering effect, elongating shorter fingers.

Marquise diamond engagement rings always have the stone mounted along the finger, which will make the finger look longer and more slender than it really is.

As one of the sparkly ‘brilliant’ cuts, the marquise can be a little more forgiving of lower clarity grades than other, less sparkly, shapes. Its fire (coloured light) and brilliance can help to hide minor imperfections and a lower colour grade.




The Bow-Tie Effect

The biggest drawback of the marquise cut is one that affects all other elongated cuts – the “bow-tie effect.” The bow-tie effect is a dark shadow that can appear in the middle of the stone when viewed from certain angles. It appears because light is reflected off the bottom of the stone and out of the sides, rather than back through the top of the diamond to the viewer’s eye.

The visibility of the bow-tie effect depends on how well each individual stone has been cut, but a well-cut diamond will dramatically reduce its visibility.

The other thing to be careful about with marquise-cut engagement rings is that the sharp points at either end and the narrow ‘girdle’ (the edge that runs around the stone) are relatively delicate, which makes it vulnerable to being chipped if it is hit on a hard surface.

Although diamonds are the hardest naturally occurring material, they do nevertheless require care, and this should be taken into account, as someone who is prone to occasional acts of clumsiness might be better suited to another elongated style which is cut without the exposed points of the marquise cut. An oval cut might, in this case, be a wise choice.

Despite being an excellent choice for style and sparkle, marquise diamond engagement rings are still something of an alternative choice. The low demand means that most brick and mortar stores will have an extremely limited choice of rings to choose from if they have any at all. However, Cape Diamonds has a much larger selection and allows you to dial in the specifications to exactly what you want.

Unlike the round, brilliant cut, most laboratories don’t grade marquise diamonds with an overall “cut grade,” which definitely makes it a bit more difficult to ensure that you’re getting a quality stone. So, in this section we’ll take a look at what you should take into consideration,  to ensure that you get the most brilliant stone possible while reducing the bow-tie effect.


Length to Width Ratio

The length to width ratio is the ratio between the length of the stone and the width. This is important for a number of reasons. The first is due to the effect that this has on the stone’s overall proportions. A lower length/ width ratio will result in a stone that looks shorter and wider, while a high ratio will result in a stone that is longer and skinnier. Usually, a ratio of 1.75:1 to 2:1 results in stones that look visually pleasing. The exact ratio that you go for is down to personal preference and should be guided by your individual taste.

Another reason that the length/width ratio is important is due to the effect that the ratio can have on the visibility of the bow tie, as a stone with a ratio over 2.1 is more likely to have a significantly visible bow-tie effect. However, the only way to really judge how visible the bow tie will be is to examine the stone that you are considering buying.


Marquise Diamond Shape & Symmetry

Symmetry is important for marquise settings in order to ensure that the stone not only looks good but also reflects light properly. The two ends should be in line with each other and the two sides should be mirror images of each other.

If possible, it’s best to be able to see the actual stone that you are looking to purchase. However, if there are no images available of the stone online then you can rely on the grading report, as long as it is from a reputable certifying agency – sticking to either GIA or AGS is our recommendation. You should be looking for “excellent” or “very good” as the minimum symmetry grading on the report.


Depth & Table Percentage

Depth percentage is the ratio of the depth to the width of the stone and has a less obvious effect on the overall appearance of an oval diamond as compared to some other shapes, but does play a big part in how prominent the bow-tie effect is. It can also affect how much light is reflected back to your eyes and therefore how much the diamond will sparkle.

Aim for a depth % within the “excellent” range of 61% to 67%. The “table” of a diamond is the large, flat area on the top of the stone, the size of which in relation to the rest of the stone is important, as the table is where the majority of light enters the stone. This needs to be carefully balanced with the other proportions in order to ensure that the correct amount of light enters the stone to allow for maximum sparkle. A larger table is not always better.


If you can, look for a marquise diamond with a table percentage within the “excellent” range to ensure that you get the best sparkle. The “very good” table range will also mean that your diamond will perform well.


Colour Grade & Deviation

Most brilliant cuts are quite forgiving of a lower colour grade. The sparkle and brilliance that the cut generates can hide the true colour of the stone, meaning that you can go slightly lower on the colour grading scale without it being immediately noticeable. However, while it is a brilliant-cut diamond, marquise stones are different.

The points of the stones tend to concentrate the colour and make the stone appear darker, so any yellow tones will show up much more clearly. Therefore, despite the forgiving nature of the cut in terms of colour grading, it is nevertheless advisable to both carefully consider the desired colour grade, and to inspect the stone either in person or using high definition photographs, comparing the stone to stones of higher and lower colour grades.

The image clearly illustrates this, as the middle of the diamond is quite colourless, but the points have a much warmer, almost yellow colour. So, while with some shapes you can safely go to “I” on the colour scale without risk of a noticeably yellow colour, with marquise engagement rings we recommend “G” as the minimum colour grade if you want your stone to appear white.

If you go lower than “G”, then your stone won’t necessarily immediately look yellow, but it will have warmer tones as opposed to the ice-white that many people are looking for in their diamonds.

Once again, the pointed ends of marquise diamonds mean that you will have to consider a slightly higher clarity rating than with other brilliant cut stones in order to ensure that any inclusions aren’t visible. Going with a VS2 grading or above will ensure that your stone is eye clean throughout.

If you are considering a “Slightly Included” stone (either SI1 or SI2), then make sure that you can get a high-quality magnified image of the exact stone that you’re investigating, to make sure that there are no visible flaws.


Carat Weight

Carat weight is something that is often given undue importance, as in seeking to choose a stone with certain carat weight, buyers compromise on other, more important attributes of the ring. The relationship between a diamond’s carat weight and its visible size isn’t always a direct one. When we judge a diamond’s size, we look at it from the top – known as the “face-up” position in the jewellery trade. However, much of the weight of a diamond is actually carried on the bottom half of the stone, where it can’t be seen.

Increasing the carat weight doesn’t necessarily translate into a visibly larger diamond. Changing the size of a stone from 0.8 carats to 1 carat is an increase in width of less than 0.4mm – less than 10%. However, the difference in price is much more significant – over 75%


Diamond Certificates

When looking at any diamond, you need to ensure that it is a “cert stone,” which means that it has been assessed, graded, and coded with a laser by an independent lab.

Each certificate has a unique report number and detailed information regarding the stone, covering the four Cs, the height, depth, and other information. As well as providing assurance that the stone that you’re buying is the quality that you are paying for, a certificate also proves that what you’re buying is not a substitute.

The lab to trust for certification is the non-profit Gemological Institute of America (GIA). It’s the most internationally recognised certification body and is generally seen as the most impartial of all of the gem labs. The reason that the GIA is so well-respected is that most other labs are part of trade bodies that include jewellery retailers, or are “for profit.”


While the GIA is very consistent with its gradings, the other labs have a reputation for being overly generous. What the GIA grades as a diamond with a “good” cut, can be graded as having an “excellent” cut by another lab, with a corresponding escalation in price.

Diamond certificates are what make buying online safe and it’s the best way to get a fantastic diamond at the lowest possible price. Knowing that each diamond you’re considering has been measured and graded by independent experts allows you to make an informed decision. You can take your time to consider the differences between diamonds and make sure you choose what experts have graded as the best stone, meaning that you get the perfect engagement ring at the best possible price.

Making a final decision on a diamond can be intimidating, so Cape Diamonds offers completely free advice to make sure you’re 100% confident in purchasing the highest quality diamond and the most beautiful engagement ring for your budget. Just answer the questions on the chatbot below and we’ll get back to you with an easy-to-understand answer or a personalized diamond recommendation. There will be no more uncertainty, as with our advice, you can be confident in your choice.