Oval Cut Diamond Guide (Everything you need to know!)

Oval Diamonds are one of the most popular styles of Diamond cut but there are some things that are unique to Ovals that you need to know about in order to find the perfect stone, which is what I am going to cover in this post.

But what do I know about Oval Diamonds? I’m Paul Haywood FGA DGA and I’m a fully qualified gemologist with over a decade’s worth of experience in the industry, 7 years of which were running my own online retailer.

I’m not going to cover general things about Diamonds as I’ve already done that in my Beginner’s Guide to Diamonds (I’d recommend taking a look if you are new to Diamonds), I will just be looking at things specifically relating to Oval Cut Diamonds.

Oval Cut Diamond Color

When it comes to color in Oval Diamonds, there are some things to consider:

In larger stones (generally ones weighing more than 2 carats), color can be more noticeable and you may be able to start noticing this from a H color onwards, so if you want a colorless stone, then go for a D-G grade
Due to the elongated style, color may be more concentrated towards the tips of the stone
The color of the metal you are putting the stone into can affect how the color looks, for example, a stone with a slight tint will look more obvious in a Platinum or White Gold setting

E Color Oval Cut Diamond — E Color Diamond

G Color Oval Cut Diamond — G Color Diamond

I color oval cut Diamond — I Color Diamond

Oval Cut Diamond Ideal Proportions

Oval Cut Diamonds are not currently given a cut grade by the GIA (or any other reputable gem lab) and this means that there aren’t any official proportions for what is and isn’t ideal, like you get with Round Brilliant Cuts.

But there are some industry recommendations as to what is ideal, good and poor and I’ve included these in the table below:

	Ideal	Good	Poor
Depth %	58 – 62	53 – 57.9 or 62.1 – 71	>53 or <71
Table %	53 – 63	50 – 52.9 or 63.1 – 68	>50 or <68
Length to Width Ratio	1.30 – 1.50	1.20 – 1.29 or 1.51 – 1.65	>1.20 or <1.65
Girdle Thickness	Thin – Slightly Thick	Very Thin – Thick	Extremely Thin – Extremely Thick
Culet Size	None – Very Small	Small – Medium	>Medium

But and this is a big BUT, these should be taken as guidelines only and just because a stone fits into the ‘ideal’ category on paper, it doesn’t gurantee that it will look good in person.

All this may not mean much to you but I will break all of these down in more detail below:

Oval Cut Diamond Depth Percentage

If you aren’t sure what depth percentage is, it is the total depth of the stone (the crown height, pavilion depth and gridle thickness) as a percentage of the width of the Diamond, for example:

If you have a 6x4mm Oval that has a depth of 2.44mm, the depth percentage is 61% as 2.44 is 61% of 4

As for the importance of this when choosing an Oval Diamond, I wouldn’t put this too high on the list as most stones will fall in the ideal to good range and because the depth percentage figure doesn’t provide enough information about the proportions of the stone.

Oval Cut Diamond Table Size

The table size is the size of the table as a percentage of the width of the Diamond and it does have an impact on how much fire (the rainbow colors seen in a Diamond) and brilliance (the amount of light returned to the eye) is seen in a Diamond.

An Oval Diamond with an ideal table size is going to have a good balance of fire and brilliance
An Oval Diamond with a small table is going to have a lot of fire but might not look very bright due to less light being returned
An Oval Diamond with a larger table will be brighter but the lack of fire can make it look dull and lifeless

Diamond cut proportions - small table — Small table: More fire but less brilliance

Diamond cut proportions - ideal table size — Ideal table size: Good mix of fire and brilliance

Diamond cut proportions - large table — Large table: More brilliance but less fire

Oval Cut Diamond Length-to-Width Ratio

Some people put a lot of importance on the length-to-width ratio, especially in relation to bow tie effect (which I will cover in more detail later) but when it comes to choosing a ratio, it comes down to personal preference as to which one you prefer but a quick breakdown is:

A ratio of less than 1.30 will have a more rounded shape
A ratio of 1.30 – 1.50 will have a traditional oval shape
A ratio greater than 1.50 will have a more elongated shape

An Oval Diamond with a length to width ratio of 1.26 — An Oval Diamond with a length-to-width ratio of 1.26

Oval Cut diamond with bow tie effect — An Oval Diamond with a length-to-width ratio of 1.42

Subtle bow tie effect in a Diamond with a 1.65 length to width ratio — An Oval Diamond with a length-to-width ratio of 1.65

What you may find is that there are less stones to choose from with a ratio of less than 1.30 or greater than 1.50 as many suppliers prefer to stock stones that fall in the ‘ideal’ range.

Girdle Thickness

Girdle thickness is also something you want to pay attention to as:

Diamonds with Extremely Thin or Very Thin girdles can have durability issues as the very thin edge can get chipped quite easily
With Thick and especially Extremely Thick girdles, you are paying for additional weight but not getting a bigger stone

That is why it is best to go for a Diamond with a Thin, Medium or Slightly Thick girdle as it provides enough durability without paying for additional weight.

You will see two measurements, for example, Thin to Slightly Thick when looking at a Diamond report and this is because the girdle isn’t the same size all the way around the stone so they provide the smallest and largest measurements.

Bow Tie Effect In Oval Cut Diamonds

One of the biggest issues with Oval Diamonds is what is known as the bow tie effect, which is a dark area across the center of the stone that resembles a bow tie.

But what causes the bow tie effect in Oval Cut Diamonds?

It is actually a really simple answer… Reflections. The dark spot you see in the stone is the reflection of your head and shoulders if you are looking at the stone in person or the camera if you are looking at a picture/video.

An Oval Cut Diamond with subtle bow tie effect — An Oval Cut Diamond with a subtle bow tie effect

A Diagram of an Oval Cut Diamond showing where the bow tie effect is seen

How can you avoid getting a Diamond with a bow tie?

You can’t completely as all Oval Cut Diamonds will have some degree of bow tie, it is just more obvious in some stones than others (as you can see in the pictures above) and it all comes down to how well the Diamond has been cut.

And the only way to find a stone with a minimal bow tie is to look at the stone, no matter what people may say going for a stone with ideal proportions is not going to guarantee that the stone doesn’t have a bow tie and I’ve included images in this post that prove it:

The Diamond just above that shows th obvious bow tie falls perfectly in the ‘ideal’ proportions
The Diamond with the length-to-width ratio of 1.65 falls in the ‘poor’ proportions but has minimal bow tie

Symmetry

Symmetry is important when it comes to Oval Diamonds as a stone with good symmetry is going to look a lot better than one with poor symmetry.

It is also one of the easier ones to think about as similar to the image above, imagine running a line down the center of the stone and checking if the left looks the same as the right and the important things for symmetry are:

That the stone has an even outline
The table is centered
The culet is centered

Fortunately, you don’t have to figure this out for yourself as labs like the GIA grade this for you on a scale from Excellent to Poor and it is best to go for a stone with an Excellent or Very Good symmetry grade.

Oval 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 Oval 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 = 6.5 x 4.4mm

0.75 Carats = 7.2 x 5.1mm

1 Carat = 7.8 x 5.7mm

2 Carat = 9.4 x 7.4mm

3 Carat = 10.6 x 8.5mm

The images above aren’t to scale as this is very difficult to do with different sizes screens and resolutions!

Due to their elongated shape, a well cut 1 carat Oval Cut will look bigger than a 1 carat Round Brilliant and this means that they are definitely worth considering for people who want more presence from their Diamond.

And the elongated shape means that they can be great option for people with longer fingers.

Oval Cut Diamond Price

Prices for Oval Cuts are usually slightly lower per carat than the equivalent Round Brilliant Cut, this is very much due to this style of cut being consistently very popular as Ovals rarely go out of fashion as it is very much a timeless style.

If you want to see the latest Oval Cut prices, then check out our Diamond Price guide, which I update every month.

Conclusion & Recommendations

Hopefully you now have a better idea as to what to look for in Oval Cut Diamonds but what if you just want some recommendations?

I’m going to base this on someone looking for a colorless Oval Cut Diamond:

F, G or H color
VS1 – SI1 Clarity
A subtle or very faint bow tie
Excellent or Very Good Symmetry and Polish

You then just need to decide whether you want a Natural or Lab-grown Diamond.