Choosing the perfect oval cut diamond can be challenging, as there is no official lab grading system for this particular cut. It can be difficult to distinguish between a well-cut oval diamond and a poorly cut one. Here are some important factors to consider when selecting the perfect oval diamond:

Measurements and girdle thickness

Pay attention to the depth, table, and girdle thickness of the diamond. A depth of 58-62% is considered excellent, while a depth of 51-68% is considered good. For the table, an excellent range is 53-63%, while a good range is 51-68%. As for girdle thickness, excellent stones have a very thin to slightly thick girdle, while good stones have a very thin to very thick girdle.

Length to width ratio

Oval diamonds come in different shapes, and the best shape for your hand will depend on the length to width ratio (L/W). An optimal range for the L/W ratio is 1.30 to 1.50. A value lower than 1.30 will result in a rounder appearance, while a value over 1.50 will make the diamond appear too long and thin.

The Bowtie Effect

Approximately 90% of oval diamonds have a dark triangular shape in the center, known as the bowtie effect. This is caused by light leakage due to a lack of reflection in that area.

The intensity of the bowtie effect can vary, with some being easy to spot and affecting the brilliance and sparkle of the stone, while others are subtle and unnoticeable to the naked eye. Be sure to examine the diamond closely with a loupe or high-resolution 360 video to ensure there is no noticeable bowtie effect.

Colour and clarity

Due to their elongated shape and large table, oval diamonds require higher colour and clarity grades than other diamond shapes. We recommend a colour grade of G or higher to avoid brown or yellow hues, and a clarity grade of VS2 or higher to minimize visible imperfections.

Oval Vs Round 

keep in mind that oval diamonds are generally less expensive than round brilliant cut diamonds of the same quality, colour, clarity, and carat weight. On average, oval diamonds are 20-24% cheaper than comparable round diamonds.

While oval diamonds may not be rare, finding a perfectly cut oval diamond with the best sparkle and brilliance is quite rare. If you have any questions or need guidance designing your dream oval diamond ring, don't hesitate to reach out to us at or book a virtual appointment 


December 20, 2022 — Amr Ramadan’s

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