Round Diamond

The Round diamond is considered superior to the fancier diamond shapes because of the breath-taking sparkle it provides. This is because virtually all Round diamonds are brilliant cut, which ensures maximum light reflection and brightness. Because of this, it is hardly surprising that the Round diamond is the most popular of all cuts, accounting for more than 50 per cent of diamonds sold worldwide.

In short: The round brilliant is the most popular diamond shape worldwide and dominates the UK engagement-ring market at 60-70% of 2025 sales. Standard cut has 57 or 58 facets (depending on culet), designed by Marcel Tolkowsky in 1919 for maximum light return. GIA's Excellent cut grade requires table 53-58%, depth 59-62.5%, crown angle 34-35°. Mohs 10 throughout. Lab-grown rounds run 60-80% below natural at identical 4Cs.

Please note that when we refer to the diamond ‘cut’ in terms of the diamond’s shape, it is not to be confused with the diamond’s actual cut, which refers to the proportions of the diamond and how well polished it has been from the raw material. You can discover more about this by heading to the cut section.

01

AN INTRODUCTION

The Round diamond is unique because the propor tions of this cut maximise fire and brilliance. It is extremely versatile, boasting a timeless and classic design. If you are struggling to choose an engagement ring for the lucky lady in your life, this is a safe bet. There are many examples of this diamond in history, but it wasn’t until 1919 that the modern Round Brilliant diamond was created.

02

FEATURES

The Round Brilliant cut is the most researched in history and it accounts for the most diamonds sold. For many, many years, diamond cutters have been attempting to optimise the brilliance and fire of this diamond by using precise mathematical calculations and advanced light reflection theories. What we are left with is a diamond that features 58 facets, or 57 if the culet is pointed, which are divided amongst the pavilion, girdle, and crown. It has a length/weight ratio of 1.00 -1.02. This cut naturally follows the rough diamond crystal, which yields maximum shine.

03

BUYING ADVICE

It is hard to go wrong with a Round diamond Engagement Rings. If you don’t know what to get your partner, a Round brilliant diamond is advisable. Boasting a classic appearance and a stunning sparkle, it is assured to impress. Most experts would agree that this diamond strikes the perfect balance between budget and colour, cut, and clarity grades. For most Round Brilliant diamonds, a four-prong setting is required, ensuring the centre stone is securely held. In some rare cases, a six-prong setting may be needed for large diamonds. The bezel setting is also very popular for this diamond cut.

Round diamonds cost more on a per carat basis than fancy shapes for two reasons; the demand for round diamonds is very high, and the yield (Yield refers to the weight of finished diamonds that are cut from the rough stone. Cutting a 1 carat diamond from a 2 carat rough stone would be a higher yield than cutting a 2 carat diamond from a 6 carat rough stone.) is relatively low. Because more of the rough stone is lost in the cutting of a round diamond, the cost of each carat retained is higher. A typical round diamond (for example; a 1.00 carat, F-color, VS2-clarity, Ex cut) may cost 25-35% more than a similar fancy shape.