Round Diamond Guide

About round brilliant cut diamonds

Round cut engagement rings are by far the most traditional and popular choice. Explore what makes round diamonds so sparkly, which grades to choose for your round diamond, and how much round diamonds cost.

Tips for choosing the best round diamond

  • Choose a diamond graded Excellent cut or Ideal for the best sparkle
  • Choose between VS2 to SI1 for the best value. Any inclusions will be invisible to the naked eye.
  • Choose colour grades D to F ideally, or down to H at the lowest, for a bright, colourless diamond
  • Choose Excellent symmetry and polish to ensure the perfect, balanced shape with crisp facets
  • Be prepared that round diamonds cost a little more than other shapes, starting from around £550 for a 0.30ct round lab diamond, or £1,000 for a round natural diamond

Find Your Round Diamond Ring

What are round brilliant cut diamonds?

Round brilliant cut diamonds are the most iconic diamond shape - appearing as a simple circle when viewed from above.

The circular diamond shape was first developed in the 17th Century, and the round brilliant cut shape has since been perfected. Today’s round brilliant diamonds are meticulously cut, unequivocally sparkly, with the optimum number of symmetrical facets to produce fire and brilliance. The 360 degree symmetry of the round diamond’s facets allow for light to enter and bounce around the diamond, before exiting to the viewer’s eye, producing a sparkle like no other shape.

Round Diamond Guide

Why choose a round cut diamond?

Round cut diamonds are the most versatile, style-enduring shape, suiting all setting styles from the ultra modern to celebrated classics. Around 75% of engagement rings created globally use round diamonds (around 60% amongst Queensmith clients), so the shape is a perfect choice for those seeking traditional charm. Equally, the refined nature of a round diamond lends itself well to minimalist, modern settings.

The most celebrated attribute of the round brilliant cut diamond is its incomparable sparkle. The lustrous diamond shape is cut with perfect, 360 degree symmetry to produce optimal sparkle. Whilst all brilliant cut diamonds exude sparkle, you’ll notice an Excellent cut round diamond outshines all other shapes.

How do I choose a round diamond cut?

The cut grade of a round diamond will have the most impact on the stone’s beauty than any other characteristic: the better the cut, the more lustrous, bright and fiery the diamond. A poorly cut round diamond will appear dull, and lack the signature sparkle a brilliance diamond should possess.

Round brilliant cut diamonds are graded from Excellent to Poor. Aim for an Excellent cut, or at the very least, Very Good. You should also consider only Excellent or Very Good grades for the diamond’s polish and symmetry.

How do I choose a round diamond colour?

Following the cut quality of a round diamond, the next characteristic to prioritise is the colour. Round diamond rings set in yellow gold or rose gold can get away with slightly lower colour grades than platinum rings. Poor colour grades appear yellow or brownish in tone, so the icy tone of platinum will contrast with any grade lower than F. Aim for D to F for platinum rings, and H at the very lowest for yellow or rose gold rings.

Round diamonds are versatile: they suit both traditional and super contemporary designs. The shape is classic, elegant and the sparkle is like no other shape.

Sarah Jane | Senior Gemmologist & Design Expert

How do I choose the clarity of a round diamond?

As a type of brilliant cut, round diamonds exude an incomparable sparkle. When choosing a brilliant cut diamond, you can afford to look a little lower on the clarity scale. Between VS2 to SI1 you’ll find diamonds with miniscule inclusions that are not visible to the naked eye. Any higher on the clarity scale, and you’ll notice a large price increase as flawless and near-flawless diamonds are incredibly rare.

How many facets does a round brilliant cut diamond have?

Round brilliant cut diamonds have 58 facets. The more precise and symmetrical the facets, the better the cut grade, the greater the sparkle, and the rarer the stone. The very top facet of the diamond is known as table, which is surrounded by the star and bezel facets. Around the outer edge of the diamond is the girdle, and on the underside you’ll find the lower-girdle facets, pavilion facet and at the very bottom, the singular cutlet facet.

How much does a round diamond cost?

Round cut diamonds are amongst the most expensive of diamond shapes; carat-for-carat, you can expect to pay less for other diamond shapes, such as oval, cushion, pear or princess cut diamonds. This is because diamonds are usually cut to whichever shape makes the most of the rough diamond. More diamond is wasted from the rough to cut a round shape; meaning a larger rough diamond is needed to cut a 1ct round diamond, than say, a 1ct princess cut diamond.

Another reason round brilliant cuts retail at a higher price than other shapes is simply because there is high demand for the traditional, much-loved round diamond shape. Around 75% of engagement rings are set with round brilliant cut diamonds.

A natural round diamond starts at around £1,000 for 0.30ct, or £550 for a round lab grown diamond.

How do I choose the best round diamond?

The secret to picking the best round diamond largely lies in its cut grade - find an Excellent cut round diamond, and you’ll have found a stone with incomparable sparkle and lustre.

Next, consider round diamonds between the colour grades D to F, which will appear icy and bright.

Finally, look between VS2 to SI1 clarity grade, which will look clear to the naked eye but will save on your spending considerably.

Your eye is the best judge; you may notice one diamond in particular jump out at you even if it’s graded exactly the same as the others. Get in touch to view diamonds with a gemmologist, or browse and compare round diamonds online.

The very best round diamonds are known as ‘hearts and arrows’ diamonds, where the cut, polish and symmetry of each facet is so precise, and so optimal, that they create a snowflake-like pattern, literally consisting of heart and arrow shapes. This is a phenomena only found in round diamonds, and it isn’t exactly apparent to the naked eye. You can use an ‘idealscope’ to see whether a round diamond qualifies as a hearts and arrow diamond. As with anything that can’t be seen to the naked eye, a heart and arrow diamond isn’t something to prioritise when searching for a good round diamond. Instead, focus on the cut grade, followed closely by the colour grade then clarity grade.


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