Guide To Buying Oval Cut Diamonds

Oval cut diamonds have been quite popular for use in engagement rings in recent times. Oval diamonds can look great and many people like the shape of the oval cut diamond as the rounded corners give it a more gentle attitude when compared to some of the other shapes that compete on price-per-carat.

Oval cut diamonds have enjoyed popularity since the current form of the shape was developed in the late 50's and early 60's. The shape has the same number of facets as does the round brilliant. It also shares some similarity with the pear shape diamond, as they both produce a bow-tie effect. Oval cuts are classified as a modified round brilliant with the 58 facets being arranged similarly to round brilliants.

My wife likes the oval cut diamond shape as she says that it tends to make her fingers look more slender. The softness from the rounded ends is also one of the features she likes. Who am I to say otherwise?

While there seems to be a lot going for this shape it turns out to be surprisingly difficult to choose an oval cut diamond that has high light performance.



Here are some suggestions that can help you find a great stone when you are in the market for an oval cut diamond.

    Length To Width Ratio
    Symmetry and Polish
    Understand the Bow-tie Effect
    What About Cut Grade?
    Color Guide
    Choosing the Clarity Grade
    Choosing a Setting
   

Length To Width Ratio

Once you begin searching for oval cut diamonds you will immediately notice that there are a number of different length to width ratios among these stones. Some oval cuts look slender and narrow, others look stout and fat. This means that there is plenty of room for personal preferences.

For the most part you will find that the majority of oval cut diamonds are somewhere between 1:1.4 and  1:1.5. An oval cut diamonds that is lower than that, say around 1:1.3 and it's going to look quite stout. On the other end the 1:1.5 ratios and over are considered narrow. These work well for earrings and pendants. The 1:1.4 to 1:1.5 ratio oval cut is the common ratio chosen as a center stone for engagement rings. If the ring has side stones then a ratio below 1:1.4 can also work.

Symmetry and Polish

You will no doubt have heard or read by now that the cut grade of a diamond is very important. The problem is that as of yet most grading labs do not issue a cut grade for oval cut diamonds. This makes is a bit challenging to find a well cut stone based on this aspect alone. The AGS does include a cut grade on their Diamond Quality Report. However not every jeweler has AGS graded oval cut diamonds. The most straightforward way to check for a well cut diamond is to find one whose grading report marks it as having excellent symmetry.

A grading report will show the quality, or grade, of an oval diamond's polish. A diamond's polish is very important no matter the cut (shape). This is why people place such importance on finding triple excellent diamonds: excellent cut, excellent symmetry, and excellent polish. It's the easiest and most straightforward way to find a great diamond. Even if this doesn't work for oval cut diamonds as you can't find a triple excellent oval cut at least you can find a double excellent oval diamond.

Understanding The Bow-Tie Effect

Due to the way the molecules of a diamond are arranged, diamond acts as both a mirror and a window. When part of a diamond returns all the light that enters it from a certain angle that area can look completely black. This is part of the magic of diamonds. They are very generous, giving back what almost seems like more light than they are given. In a round brilliant this can present a very attractive contrasting effect. In oval cut diamonds this presents as a dark band in the middle.

There is practically no oval cut diamond that does not have some sort of dark band in the middle. In most oval cut stones it presents as a bow tie. It's called the bow tie effect. The bow tie effect is usually preferred  having a conspicuously large dark band. Some stones' bow tie effect is minimal. However whether or not an oval cut diamond has an ideal bow tie should be balanced with its overall brilliance and fire.

Remember that just because the light is not being returned to your eye in that central area of the stone does not mean it is not being returned at all. What you don't  want is a stone that is leaking light through its sides and pavilion.

What About Cut Grade?

The shape of an oval cut diamond does not permit it to return light in a way that is comparable to a round brilliant. This is one of the reasons oval cut diamonds are 25-27% cheaper than round brilliants. AGS graded oval cut diamonds usually max out at 1 where the highest cut grade is 0. I am happy for someone to prove me wrong, but I haven't come across any AGS Excellent Cut Grade (0) oval diamonds. So don't feel like you are chasing a ghost if you don't find any AGS Excellent Cut Grade (0) lab diamonds. Or maybe do. There is no oval cut that can compete with ideal cut round brilliants.


GIA is the lab of choice for a majority of diamond jewelers. This is due to the reliability and consistency of the reports they issue. GIA does not issut a cut grade for fancy cut diamonds, including ovals. They do however include some of the important measurements which experienced diamond handlers can use to identify a well cut diamond.

Here are my general cut parameters for the best oval cut diamonds:



    Table: 51% to 64%
    Depth: 58% to 66%
    Girdle: Very thin to slightly thick
    Culet: None

 These are not hard and fast rules. Some diamond experts have slightly different recommendations.
An oval diamond can be brilliant, well-proportioned and beautiful in appearance but if you don't get a look at the diamond you can't be sure. Check out my list of places to buy oval cut diamonds online for some ideas on how to get a look at the diamond before buying.

Color Grade

A fascinating phenomenon we find in diamonds is that when they return light efficiently the color of the diamond becomes less apparent. Oval cut diamonds are the most efficient around the center area which has a similar to round brilliants. The color is usually harder to detect in the center area due to this effect. This means of course that a lower color grade, ie darker, oval diamonds are going to show distinct color phasing between the efficient area and the less efficient areas. That's not going to be an issue if the diamond is a D-E-F. Once you get past G the color starts showing more. G-H-I-J round brilliants don't show much color if they are ideal cut. Ovals from the H-I-J and lower color grades however can never look colorless no matter how good the cut because the geometry of oval diamonds will not permit it.

The Best Clarity For Oval Cut Diamonds

All brilliant cut diamonds are dazzling enough to make inclusions difficult to see.

The sweetspot is VS2, just as with round brilliants, cushion cuts and princess cuts. SI1 and SI2 can sometimes yield good results too and it can be worth looking through these clarity grades for something that looks relatively eye-clean.

Choosing a Setting

Because the oval shape does not have any pointed edges, it is not as vulnerable as cuts that have pointed edges, like marquise or pear cuts. The classic setting for any diamond is the solitaire setting.  For the best look, choose a prong setting as this allows for the maximum amount of light reflection and visibility of the diamond.

Depending on the size of the stone, you can choose a 4 prong, 6 prong or 8 prong. Of course, the higher the number of prongs, the greater the security and the more accentuated the shape, but the lower the visibility of the diamond.

Another excellent setting for oval diamonds is the halo setting. This adds extra sparkle and maximizes the diamond’s look. A halo setting also tends to accentuate the elongated shape of the diamond and sets it apart from other diamond cuts.

Halo settings are popular for oval cut diamonds, as are three stone settings. 

There are some beautiful vintage style designs around which work well too.

Some other great choices are three stone setting, side stone and pave. If you want something different for your oval diamond ring a tension setting might do the trick.

All About Step Cut Diamonds: Emerald, Asscher, and Baguette

Is far as diamonds go, alike shapes are grouped together into similar categories: first we have brilliant, then we have the step cuts, then there's mixed, and last of all rose. We may also call them families. So each of these diamond families has its own qualities and hence its own fan club. Getting the best diamond will be different depending on which fan club you belong to.

It's important to not apply round brilliant diamond buying tips to emerald cut diamond buying tips.

A Quick Introduction To Step Cuts

A step cut diamond's most notable feature are the eight lines running down the sides. These draw the viewer’s attention to the middle of the stone. The second feature of not are the stepped facets that run along the diamond's length as well as its width. These go in parallel lines, which might remind you of the steps of Meso-American temple pyramid. The diamond facets are for the most part bigger than the ones found in round brilliant and princess cut diamonds. They are arranged in such a way to resemble steps, so the name makes sense. Step cut diamonds are known for an effect called the “hall of mirrors” effect.

How Many Different Step Cut Diamonds Are There?

There are three different diamond cuts that can be categorised as belonging to the the step cut family. These are emerald cut, Asscher cut, and the lovely and delicious sounding baguette cut. Asscher cut diamonds and emerald cut diamonds are used in engagement rings more frequently than baguette diamonds. Baguette diamonds work better as accents or as a pave, or eternity ring.

 Comparing Step Cut Diamond Shapes

Emerald

Emerald cut diamonds have cropped corners and a large table with an elongated pavilion. They are known for their elegant rectangular shape.

Asscher

X marks the spot. Asscher diamonds are known for the distinctive ‘X’ visible in its table, this square diamond shape has cropped corners and almost hypnotic pattern created by the arrangement of the facets at specific angles.

Baguette

This thin, rectangular diamond has fewer facets than we find in emerald cut diamonds and Asscher cut diamond. Baguette diamonds are not usually used as a feature stone. They are commonly used as accent stones or in other types of jewelry, like eternity rings and bracelets.

What Are The Characteristics of All Step Cut Diamonds?

Stepped cut diamonds have two very specific characteristics. Firstly, step cut diamonds all have a rectangular shape or a square shape. Secondly, the diamond’s facets need to be rectilinear. that is to say they must be made up of straight lines that run parallel to the stone’s girdle.

5 Tips: Step Cut Diamond Shopping

Step cut diamonds have their own unique set of guidelines so it's crucial to not think that any and all advice will apply. These 5 tips will help you as you work on finding your ideal step cut diamond. the goal as always is to get the very best step cut diamond that is perfect just for you.

1. Higher Clarity and Color Grades  

If you don't know what the 4C's are then get yourself up to speed on any diamond jeweler's website.

Clarity is one of the most important considerations when shopping for any step cut gem. Emerald cut diamonds in particular. this is due to the fact that step cuts diamonds have a large, open table. They also give the appearance of having less facets than mixed or brilliant cut diamonds. This makes is much easier to spot inclusions. What I am saying is that the flaws in a step cut diamond will be hard to miss in an emerald cut diamond when compared to a round brilliant cut diamond. A high clarity grade is always absolutely worth it.

After a shot while learning about diamonds you will run across the statement that "cut is the most important factor". This is referring to how symmetrical and well proportioned the diamond is. Diamond cut designs are designed to make the diamond perform with the maximum amount of brilliance and sparkle. howe close the cutter gets the diamond to conform to this ideal shape is how a diamond is graded in terms of "cut". Grading laboratories don’t actually assign cut grades to step cut diamonds, as there is too much variation possible. what we have to look for then are the polish grading and the symmetry grading. If together, polish and symmetry, are excellent and you have a top clarity grade clarity you will have a pretty good idea of the diamond's quality and brilliance. So choose step cut diamonds that have Excellent polish, Excellent symmetry and a clarity grade of VVS2 or higher. This combination will give you the most sparkle.

Many diamond jewelers do label their listed step cuts with a “Very Good Cut” or “Good Cut”  grade by checking the grade of the diamond's proportions, symmetry, polish. This can help a great deal, though remember that a cut grade assigned to any step cut diamond is only a general guide, and not the opinion given by a diamond grading lab.

2. Step Cuts Are Excellent For Vintage Engagement Rings

If you are looking for a vintage-inspired or antique style of jewelry, step cuts will give you an authentic look.

The Asscher diamond was a shape that was designed by a man called Joseph Asscher in 1902, and while it has always been a rare, unusual choice for engagement rings, it soon gained popularity among elite fashion circles; one of the most famous Asscher cut diamonds in the world is insanely large emerald cut diamond known as the Krupp, a staggering 33.19-carat gem purchased for Liz Taylor at the cost of $305,000 in 1968 by her husband Richard Burton.

Emerald cut engagement rings reached the peak of their popularity in the mid-20th century, boosted by being the choice of stars such as Grace Kelly and Elizabeth Taylor (she wore a lot of diamonds). In recent times, the emerald cut diamond has returned into the spotlight. Well known personalities such as Beyonce, Amal Clooney, and Angelina Jolie are some of the well known examples of people that have enjoyed the elegance of the emerald cut.

 3. Step Cuts Will Save You Money

In terms of popularity, mixed and brilliant cut diamonds such as round, princess and cushion are continually best sellers. As demand for other diamond shapes increases, their prices will reflect this popularity. In turn, less popular shapes like step cuts hopefully come down in price. When you are shopping for a step cut diamond, compare prices with a round cut.
The cost per carat is not necessarily higher as the market fluctuates and the law of supply and demand dictates the price level.

4. Baguette Diamonds Are Used For Accent Stones

Baguette diamonds are a thin, rectangular cut that you will most often see as accent stones in an engagement ring or in fine jewelry. The cut of a baguette diamond is extremely shallow, which means that it doesn’t reflect as much light as other diamond shapes. As explained in the Diamond Cutting 101 post, little-to-no light reflection means little-to-no sparkle. So, a baguette diamond is better used as an accent piece for a brilliant or step cut center diamond, rather than being a center stone by itself. The three-stone engagement ring below features an Asscher center stone with two baguette diamond accents on either side.
You can add more sparkle by combining baguette diamonds with a brilliant or mixed cut diamond. Flank a cushion or princess center diamond with baguettes to create stunning contrast.
princess cut diamond with baguette side stones

5. A Step Cut Diamond Will Turn Heads

Last but not least, there’s no denying that an unusual diamond tends to draw the eye. When you purchase step cut diamonds in today’s market, you are choosing a less conventional and more unique shape than most of your diamond buying peers. If you opt for an unorthodox diamond shape like a step cut, don’t be surprised if people do a double-take when they glance your diamond.

Understanding ASET diamond imaging

If you spend a bit of time checking out different diamond jewelers' websites you will eventually come across an image called an ASET image.

How to Read A diamond ASET Image

These images are created by a small reflector tube that has colors painted on the inside. As the diamond gathers light it returns light from different angles from its surroundings.

As high quality diamonds are competing for the top spot the ASET tool is valuable for determining with great precision how much better one diamond is to another. Diamonds with above average fire and brilliance are highly prized. Since the level of brilliance is a little difficult to protray over the web the ASET is one of the best tools to show how a diamond is performing.

ASET =  Angular Spectrum Evaluation Tool.

The ASET was designed by experts at the American Gemological Society (AGS). The idea was to show clearly how a diamond handles light. ASET is now the tool that provides one of the most quantifiable results on diamond light performance. A jeweler or gemologist can use the ASET to demonstrate the light performance of a diamond. It's a great way of understanding the difference between different proportions.

ASET images

An example of several ASET images


ASET images are made up of the three colors that are reflected from the interior of the little ASET tube: red, blue, and green. These colors show how the light passing through a diamond is returned to the eye. Diamond facets have the amazing properties of acting as both windows and mirrors. Different angles of light collection by the diamond are shown in the image as different colors. The red color is the light collected from the higher angles, essentially the light collected from above. Green indicates returned light from lower angled light sources. Blue sections represent areas of contrast, these are the areas usually blocked by the head of the viewer which causes an effect called obscuration. As high contrast in diamond is seen to be a favorable trait strong blue arrows indicate that the diamond has good contrast.

ASET as a concept is not complicated. You look at a diamond through the top of a semi-sphere that has been painted with colors that mark the angular ranges. When the light is gathered by the diamond (instantaneously, by the way) the diamond has the different colors showing through the diamond. It will indicate areas of the diamond that are gather light from different angles as well as show the areas that are not  returning light.  This is called light leakage. Because light from different ranges above the horizon has different attributes, the ASET tool can provide important insight about how the diamond handles light. Easy? Good.