Marquise Cut Diamond Guide – What You Need To Know!
With its elongated shape and pointed tips, Marquise Cut Diamonds are one of the more unique styles of Diamond cut and if you are looking for one of these stones, then there are some things you need to know, which is what I will cover in this guide.
If you are new to Diamonds, I would recommend checking out my Beginner’s Guide to Diamonds, as this covers all of the basics as this guide is focused on things relating specifically to Marquise Cuts.
Table of Contents
- Marquise Cut Diamond Colour
- Marquise Cut Diamond Ideal Proportions
- Marquise Cut Diamonds Length-to-Width Ratio
- Marquise Cut Diamond Shape
- Marquise Cut Diamond Depth Percentage
- Marquise Cut Diamond Table Size
- Girdle Thickness
- Bow Tie Effect In Marquise Cut Diamonds
- Symmetry
- Marquise Cut Carat
- Marquise Cut Price
- Conclusion and Recommendations
Marquise Cut Diamond Colour
When it comes to colour in Marquise Cut Diamonds, there are a couple of things to be aware of:
- Due to the style of cut, colour is often more noticeable at the points of the stone, to avoid this, it can be advisable to go one or two grades higher
- If you want a colourless stone, then go for a D-G grade. H can also be colourless when face up but you would need to inspect the stone for yourself
- Colour starts to become easily noticeable at a I colour grade
Marquise Cut Diamond Ideal Proportions
Currently, the GIA doesn’t give a cut grade for Marquise Cut Diamonds but IGI does and this provides us with some useful information regarding the proportions they require for a stone to be given an Excellent cut grade, which can be seen in the table below:
| IGI Excellent | |
|---|---|
| Length to Width Ratio | 1.70 – 2.25 |
| Depth % | 57.5 – 64.5 |
| Table % | 56 – 64 |
| Crown Angle | 31° – 38° |
| Pavilion Angle | 39.5° – 42.5° |
| Girdle Thickness | Thin – Slightly Thick |
| Culet Size | None – Small |
It does need to be noted that proportions alone aren’t enough for a stone to be given an Excellent grade, they are also assessed on:
- How noticeable the bow tie is
- How much light the stone returns
It also doesn’t guarantee how good a stone will look, so these should be taken as guidelines only and there will be stones that fall outside of these proportions that will look amazing.
When it comes to GIA reports, they don’t provide the crown or pavilion angle, which is annoying, they only provide the total depth percentage, table size and girdle thickness.
Marquise Cut Diamonds Length-to-Width Ratio
As you can see in the proportions table, there is quite a large range for what falls into an Excellent length to width ratio but this can be difficult to visualise, so I found examples at the bottom, middle and top of the range in the images below:
As you can see from the pictures above, the length to width ratio does have a big impact on how the stone looks.
Marquise Cuts with a lower ratio have a more rounded appearance
Marquise Cuts with a higher ratio have a more slender, elongated appearance
As for which length-to-width ratio to go for? That all comes down to personal preference as some people prefer the look of one over the other but things like finger size can also be factored in, for example:
If you have long, slim fingers, a Marquise with a higher length-to-width ratio can look really good.
Some people get a little bit obsessed with the length-to-width ratio, especially in relation to things like bow tie effect (more on that later) but it really doesn’t make a huge difference as there are plenty of stones with Excellent ratios that have a very obvious bow tie, so just go for the shape you like!
Marquise Cut Diamond Shape
Following on from length-to-width is the shape of the Diamond.
When it comes to shape there are two important aspects of Marquise cuts to consider, which are the wings and the point.
With the wings, the ‘ideal’ shape is similar to the diagram above as the wings have a nice, gentle curve that gives the stone a nice outline but you can also comes across:
- Bulged wings – these give the stone a much more rounded shape (similar to 1.75 ratio stone in the picture above) and make the points of the stone appear less prominent
- Flat Wings – these stones have a much straighter line from the belly of the stone to the point
Once again, it comes down to personal preference as to which style you prefer but a lot of people like the ‘ideal’ outline and the only way to judge this is to see the stone in person as this isn’t included on reports.
Second is the point of the stone and on some stones (I couldn’t find an example unfortunately), they have very rounded ends and almost look like a very elongated Oval Cut.
Top Tip – Always use a setting style that protects the point of the stone as it is the weakest point and the most likely to get damaged if left exposed.
Marquise Cut Diamond Depth Percentage
Depth percentage is another thing that some people seem to think is really important but unless the stone is extremely shallow or thick, it really isn’t that important.
But why? The total depth percentage (which is the combined crown height, girdle thickness and pavilion depth as a percentage of the width of the stone) doesn’t give enough information about the stone’s proportions.
The proportions that are helpful (crown height and angle and pavilion depth and angle) aren’t included on GIA reports.
Marquise Cut Diamond Table Size
Table size is an important proportion as the size of the table impacts on how light interacts with the stone, as you can see in the images below:
Girdle Thickness
Girdle thickness is also something you want to pay attention to and ideally you want to buy a Diamond with a Thin to Slightly Thick girdle and you want to avoid:
- Extremely Thin girdles – due to being so thin, they can cause durability issues and the girdle can easily get chipped or damaged
- Extremely Thick girdles – these add additional weight to the stone but don’t add any size to the spread of the stone
Now you may notice on reports that they give a range, for example: medium to slightly thick, this is because there are slight variations in girdle thickness around the stone and the measurements give the smallest and largest measurement.
Bow Tie Effect In Marquise Cut Diamonds
Now we get to an important visual effect that is seen in some degree in all Marquise Cut Diamonds and that is the bow tie, which is a dark area that is seen across the centre of the stone but what causes this?
It is caused by reflections. If you are looking at the stone in person, this is your head and shoulder being reflected in the stone or if you see this on a picture/video (like the stone below), it is caused by the reflection of the camera.
The next question is how can you avoid a bow tie in a Marquise Cut Diamond?
As I said above, every stone will have some degree of bow tie but it does vary from stone to stone and the only way to find a stone with a minimal bow tie effect is to see the stone and look at it at slightly different angles, in different light sources.
Symmetry
Symmetry is an important grade for Marquise Cut Diamonds and fortunately, the GIA does give a symmetry grade ranging from Excellent to Poor.
It is also one of the easier aspects of Diamond grading to understand as it is basically putting a line down the centre of the stone and checking if the left and right sides of the stone are the same and this is important as it not only impacts how the stone looks but also how light interacts with the stone.
Marquise Cut Carat
Something many people get wrong is thinking that carat weight = size but this isn’t true.
And even though there are charts out there, such as my Marquise Cut Size to Weight chart, these should only be used as guides as the proportions vary from stone to stone, meaning two stones can have the same length and width but slightly different weights.
0.5 Carat = 6.6 x 3.3mm
0.75 Carats = 8.2 x 4.2mm
1 Carat = 10.5 x 5.25mm
2 Carat = 13.2 x 6.6mm
3 Carat = 15.0 x 7.6mm
The images above aren’t to scale as this is very difficult to do with different sizes screens and resolutions!
Due to its unique shape, a well-cut 1-carat Marquise Cut will have a larger outline than a 1-carat well-cut Round Brilliant, which can make it a good option for someone who wants their Diamond to have a bit more presence.
And as I mentioned earlier, the elongated shape means that Marquise Cuts can be great option for people with longer, slimmer fingers.
Marquise Cut Price
Marquise Cuts can sometimes have a higher price per carat than an equivalent quality Round Brilliant, this is because in many cases Marquise Cuts don’t generate a good yield from the original crystal (due to the shape of the stone).
Prices can fluctuate depending on current trends as the unique style of the Marquise can go in and out of fashion, you may also find that the selection of Marquise cuts is smaller than many other fancy cuts.
If you want to see the latest Marquise Cut prices, then check out our Diamond Price guide, which I update every month.
Conclusion and Recommendations
I’ve covered everything you need to know in order to find the right Marquise Cut Diamond for you and this is the same whether you are buying and Natural or Lab-grown Diamond.
As I have said numerous times, choosing the best stone comes down to personal preference but to make broad recommendations, I always go for:
F or G colour (H is also worth considering)
VS1 – SI1 Clarity
A stone with a subtle or very faint bow tie
Excellent or Very Good Symmetry and Polish
A report from a reputable gem lab
If you have a very large budget or want the ultimate show-off Diamond, then go for a D Flawless or as close as you can get.
I'm Paul Haywood FGA DGA, the owner and founder of Haywoods Gems, I'm a fully qualified Gemmologist and Diamond Grader from the Gemmological Association of Great Britain.