Unsure of which cut is right for you? check this out to make sure you pick the right stone

Continuing with our series on the Four C’s of Diamonds, we look in this week’s breakdown one of the most important C's that is Cut.

Why would the cut be one of the most important quality of a diamond? Well, it plays the biggest role in effecting the sparkle of the diamond, and let’s face it, the sparkle is a top priority for most.

A good cut has the power to make a diamond of lower colour and clarity look breath-taking. And yet, a diamond with the best colour and clarity can look horrible if it has a terrible cut.

The Difference Between Cut and Shape:

The first thing to know is that the term “cut” is used in two different ways. Many people use “cut” when describing a diamond’s shape, for instance, an “emerald-cut engagement ring”. Though the term is widely used in this way, it is not really the correct usage. The true definition of cut is not the shape of the diamond, but rather the proportion, polish, and symmetry of the diamond.

  • Diamond Cut Shape– The shape of the diamond. There are ten main types of cut shapes (Circle, Oval, Emerald, Radiant, Asscher, Cushion, Heart, Princess, Marquise, and Pear Cut).
  • Diamond Cut– A diamond’s proportions, polish, and symmetry.

A Gemmologist’s Take on Cut

When a professional jeweller studies a diamond’s cut, they look at a myriad of things, but in the most basic terms, their analysis concerns how the diamond reflects and refracts light.

Gemmologists determine a cut grade by studying three important kinds of light reflection:

  • Brilliance– The white light reflection on the surface and inside the diamond.
  • Fire– The flashes of colour caused by the dispersal of light inside the gem.
  • Scintillation– The flashes of light and dark (sparkle) when the diamond is moved.

Cut Grade

Like clarity, diamond cut is measured using a grade system ranging from the best cuts (Ideal) to the worst cuts (Poor):

  • Very Ideal– Proportioned to return the greatest possible light.
  • Ideal– Reflects almost all the light that enters the diamond.
  • Very Good– Reflects almost as much light as Ideal cuts but a more affordable cost.
  • Good– Reflects most of the light.
  • Fair– Not as brilliant a cut, but still a decent diamond.
  • Poor– Reflects low amount of light. These diamonds are not worth your time.

At Hamlingtons, we offer the nine most popular diamond shapes, certified by GIA. While the correct term is diamond shape, it’s also referred to as the “cut” of the diamond.


The most popular diamond shape, the round cut was invented through jewellers’ attempts to create a cut with the most facets and shine. Today, more than 75% of the world’s diamonds are cut in the brilliant style. Its 58-facet cut is calibrated according to a precise formula to achieve maximum sparkle. When cutting a rough stone, more is lost in shaping a round diamond, so the cost of each carat retained is higher. Rounds are also the most popular shape for other jewellery like necklaces and earrings.


The princess-cut diamond was created after polling women to find out what they wanted. (Imagine!) This cut is renowned for its incredible shine despite the square shape. This cut requires more weight to be directed toward the diamond’s depth to maximize brilliance. Depth percentages of 70% to 78% are common, and the ideal square ratio ranges from 1.00 to 1.05. A princess cut should always be set for four prongs to protect its corners from chips. It has 57 or 58 facets and is known as “square modified brilliant” or “rectangular modified brilliant” when the ratio is greater than 1.10.


Similar to the princess cut, the cushion-cut diamond has a relatively square shape. However, it’s available in a multitude of ratios, making it either square or rectangular. Cushion cuts blend the energy of a round brilliant with the symmetry of a radiant cut; the corners of the stone are rounded, which is great for a woman with an active lifestyle. Also known as the “pillow cut,” the cushion cut has larger faceting, which enhances brilliance. Cushion-cut diamonds have great fire (the light that is reflected out of a diamond in a rainbow of colour). Larger facets can show clarity inclusions, so evaluate the location of inclusions by examining the certificate’s diamond plot or talking to an expert gemmologist.


Oval diamonds possess the brilliance of the round cut, but they can draw more attention because of their unique shape. This is a fashionable cut because they can appear larger than a round diamond at the same carat weight. It’s also beloved for its ability to flatter the hand. The shape may have been developed to represent the longevity of a relationship, but it’s valued because the oval diamond can make one’s fingers look longer and thinner. Be careful when selecting a diamond with this style stone — the rounded ends tend to show more colour than a round diamond would, so it’s wise to go up a colour grade to ensure the ends appear colourless.


One of the first diamond cuts in the world, the emerald cut is perfect for coloured gemstones as well as high-quality diamonds. Also known as “step cut” because of the layered faceting, the emerald cut possesses unique appeal with symmetrical sparkle. The faceting is minimal and simple and therefore tends to show inclusions. An open setting can also show the diamond’s colour, so closed or bezel type settings are recommended with lower colours. If you choose an emerald cut, it’s smart not to compromise in diamond quality, because the style emphasizes the colour in the stone.


The pear-shaped diamond engagement ring is incredibly unique, which is why many women love it. A pear-shaped diamond is shaped like a teardrop, with a slightly flatter and larger bottom and a skinny point at the opposite end. With 58 facets, light dances through the diamond like a round brilliant cut, maximizing sparkle. The shape allows the wearer the option of pointing it up or down. Its faceting often masks inclusions, and those found near the point tend to be less visible. The suggested cut ratio is 1.5 to 1.7. Always set the diamond with a prong covering the point of the stone to prevent chipping.


The marquise-cut diamond has many nicknames, including the football cut, boat cut, eye cut or navette cut. Its intriguing shape and style allow the bride maximum creativity in her ring choice. A variant of round- and pear-shaped diamonds, the marquise’s elongated body can make it seem larger than its actual carat weight. It’s an excellent cut to show off long, slender fingers. The suggested cut ratio is 1.75 to 2.25.


Nearly octagonal in shape because of its curved edges, the Asscher cut has a timeless, understated effect. Step-cut facets create a soft glow emanating from the stone. It’s a blend of the princess and emerald cuts, with X-shaped facets from its corners to its centre culet. The step cut emphasizes the clarity of the diamond, and it’s ideal for showcasing higher clarity diamonds. The faceting can mask certain inclusions and lower colour grades. Its suggested cut ratio is 1.00 to 1.05 for square proportions.


A beautifully symmetrical, non-traditional cut, the radiant shape combines the brilliance of a round and the purity of an emerald cut. The radiant is considered one of the shiniest cuts of diamonds because of its 70 facets; it has a fiery look while maintaining soft, cut corners. A rectangular radiant cut is an excellent option for buyers who like the emerald-cut shape but want something with the brilliance of a round. A ratio of 1.00 to 1.05 will create a square shape, and 1.30 to 1.50 will produce a rectangle.