Round brilliant cut diamonds | A buyer’s guide

The round brilliant cut diamond is a timelessly exquisite cut of the iconic gemstone. It has consistently been one of the most popular cuts for as long as diamond rings have been on the market and it’s no wonder as to why. 

Its perfectly symmetrical nature means it strikes an amazing balance between traditional and classic, and modern trends, its versatility means it is easy to personalise and turn into a stunning, bespoke piece of engagement jewellery. In this guide, we’ll be going through everything you need to know as a buyer interested in a round brilliant cut diamond.

What is a round brilliant cut diamond?

The round brilliant cut diamond is the quintessential diamond cut, if you imagine a diamond in your mind, it’s probably the round cut you see. As the most popular shape in the industry, the round cut represents around two thirds of all diamonds sold.

In 1919, Marcel Tolkowsky started a buzz around the round brilliant cut in his work, “Diamond Design: A Study of the Reflection and Refraction of Light in Diamond” which emphasised the best aspects of a round brilliant. Since then, it has maintained its position as the most common diamond cut.

How many facets does a round brilliant cut diamond have?

This particular cut of diamond has 58 facets (including the cutlet) which offers outstanding and unparalleled white light reflection, known as brilliance. It is this feature, at least in part, that is behind the reason why the round brilliant is used so much in engagement rings, necklaces, and other fine pieces of jewellery. Keep in mind that the term “round cut” refers to the shape of the diamond, so if someone mentions round cut, round brilliant cut, or round shaped diamond, it all means the same thing.

Why are round brilliant diamond engagement rings so popular?

There are several reasons why round cut diamonds are so in demand for engagement rings, let’s take a look at the main ones below.


Round brilliant cut diamonds are unlike anything else, they’re truly exceptional. The 58 diamond facets all reflect light back to your eyes, creating the bright sparkle that is synonymous with the stone. For more than 100 years, diamond cutters have been perfecting the craft of cutting round brilliant diamonds. The result of this is a beautiful gemstone that can made into a unique engagement ring by an expert jeweller like Barbara Tipple.


As mentioned above, brilliance is what gives a diamond its sparkle. It refers to the amount of white light reflecting off the diamond and the best cut aspects of a round cut has more brilliance than any other shape. This is why they are always so eye-catching.


The round brilliant boasts a classic design, meaning it can complement a wide variety of styles whether you’re looking for a modern round cut ring or a vintage engagement ring. Round cuts are also commonly used for side stones as well as the main feature stone.

Cut quality of a round brilliant diamond ring

Of all its features, the cut quality is the one that most heavily effects a diamond’s beauty. It involves how well-proportioned and visually appealing a diamond is, so the cut quality will impact the stone’s ability to reflect light and create brilliance. A badly cut round diamond will end up being dull or unevenly proportioned, rendering all other characteristics of the ring pretty much irrelevant.

When a round brilliant diamond is cut too shallow, incoming light will hit it at a lower angle. The light then moves through the diamond and goes out of the sides without reflecting and sparkling. So, the large amount of escaping light means the diamond ends up losing brilliance.

If a diamond is cut too deep, light will hit the pavilion at a shorter angle, pushing the light to reflect to another pavilion and leave through the bottom of the stone. This means it will be dull instead of bright and radiant. 

To ensure you get a high quality round brilliant cut diamond, purchasing your jewellery through a professional, bespoke jeweller like Barbara is the best approach. You’ll get a one-of-a-kind ring design and assurance that only highest standard of materials has been used to create it.


Round brilliant cut diamonds are a traditional and beautiful choice for an engagement ring. If your partner loves the look of a classic diamond, then this is the cut you should choose.

Barbara Tipple is an award-winning jeweller who designs and creates stunning bespoke engagement rings. With extensive experience in the industry, she can bring your vision of the perfect ring to life. Contact us today to arrange a discussion with Barbara.