Princess Cut Diamond Guide – What You Need To Know!
The Princess Cut is one of the most popular styles of Diamond cut, with it square shape appealing to many people (I think the name also helps its popularity) but as with all fancy Diamond cuts, there are some things you need to know, which is why I created 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 Princess Cuts.
Table of Contents
- Princess Cut Diamond Colour
- Princess Cut Diamond Clarity
- Princess Cut Diamond Ideal Proportions
- Princess Cut Diamond Chevrons
- Princess Cut Diamonds Length-to-Width Ratio
- Princess Cut Diamond Depth Percentage
- Princess Cut Diamond Table Size
- Girdle Thickness
- Symmetry
- Princess Cut Carat
- Princess Cut Price
- Conclusion
Princess Cut Diamond Colour
When it comes to colour, Princess cut Diamonds aren’t quite as good as Round Brilliant stones when it comes to masking colour, which is why:
- If you want a completely colourless stone, then go for one in the D-F range
- G colour grades will also be colourless when viewed face up but don’t have the same crispness of a D-F stone (as can be seen in the images below)
- A hint of colour starts to become noticeable at a H grade and more so as you move further down the scale and a H-J grade can be good for people who prefer a warmer look
Princess Cut Diamond Clarity
When it comes to clarity is Princess Cuts, there are two main things to consider:
- Due to having larger tables, there is more chance that inclusions may be visible under the table than in some other styles if brilliant cut
- With lower clarity grades, care should be taken with inclusions that are in the corners as they can (not always) cause some durability issues
Princess Cut Diamond Ideal Proportions
Currently, the GIA doesn’t give a cut grade for Princess 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 | 1.00 – 1.05 |
| Depth % | 65 – 73 |
| Table % | 65 – 74 |
| Crown Height % | 8 – 14.5 |
| Pavilion Depth % | 54.5 – 62 |
| 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 visible the chevrons are when the stone is viewed face-up
- How even and symmetrical the chevrons are
- The quality of light return
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.
Princess Cut Diamond Chevrons
As I just mentioned chevrons above, let’s take a look as to what this actually means when it comes to Princess cuts.
The way the facets on the pavilion of a princess cut have been designed, means that they resemble a chevron and the number of chevrons varies from stone to stone, with some having just two but some stones can have five or more.
But what difference do these make to the look of the stone?
Basically, the more chevrons there are, the more facets there are for light to reflect from and this can increase scintillation and give the stone more of a crushed ice look.
As to how many chevrons to go for? That all comes down to personal preference as to which design you prefer and while you can get an idea of this from pictures and videos, this is best seen in person.
Princess Cut Diamonds Length-to-Width Ratio
The majority of Princess cut Diamonds fall in the 1.00 – 1.05 range and will look square to the naked eye, it is only really noticeable if you have a 1.00 and 1.05 in front of you and:
- A Princess Cut with a 1.00 ratio will be perfectly square
- A Princess Cut with a 1.05 ratio will have one side that is very slightly longer than the other
There are some rare Princess cuts that have an elongated shape that is greater than 1.05 but they can be hard to find as most people want their stone to be square.
Princess 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.
Princess Cut Diamond Table Size
Table size is an important proportion as the size of the table impacts how light interacts with the stone, as you can see in the images below (I know they are round brilliant diagrams, but it should give you an idea!):
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.
Symmetry
Symmetry is a really important quality factor for Princess Cut Diamonds and even small symmetry defects can be really noticeable due to the geometric shape of the stone, with things like:
Outline – are all sides and corners of the stone even
Chevrons being even on all sides
Table and culet being centred
All playing a part in the symmetry grade the stone gets but fortunately, the GIA does give all princess stones a symmetry grade.
Princess Cut Carat
The weight of the Diamond you buy is going to depend on your budget and generally, the more the stone weighs, the more expensive it will be but one thing to be aware of is that the weight of a Diamond doesn’t directly correlate to size.
And even though there are charts out there, such as my Princess 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.
1/4 Carat = 3.5-3.6mm
1/2 Carat = 4.4-4.5mm
1 Carat = 5.5-5.6mm
2 Carat = 7-7.1mm
3 Carat = 8-8.1mm
The images above aren’t to scale as this is very difficult to do with different sizes screens and resolutions!
Due to its shape, a well-cut 1-carat Princess Cut will have a smaller outline than a 1-carat well-cut Round Brilliant, which means that if you want the size, you will have to go for a higher carat weight.
Princess Cut Price
Prices for Princess Cuts are usually lower per carat than the equivalent Round Brilliant Cut and even though they are quite resilient to changes in fashion trends, the prices can still fluctuate a little bit and they are not as popular as the Round Brilliant.
If you want to see the latest Princess Cut prices, then check out our Diamond Price guide, which I update every month.
Conclusion
I’ve covered everything you need to know in order to buy the right Princess Cut Diamond for you and this is the same whether you are buying and Natural or Lab-grown Diamond.
To summarize again, for the majority of buyers I would recommend buying a:
F or G for colourless, H or I if you prefer warmer tones
VS1 – SI1 Clarity
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.