THE 4 Cs OF DIAMOND QUALITY

When buying a diamond, understanding its quality is essential. Experts evaluate diamonds based on four key factors known as the 4 Cs: Cut, Color, Clarity, and Carat weight. These characteristics determine not only how a diamond looks, but also its overall value.

CUT

What it means

Cut refers to how well a diamond has been shaped and faceted, not its shape (round, oval, etc.). It determines how light enters and exits the diamond—this is what creates brilliance (sparkle).

Why it matters

Even a flawless diamond can look dull if the cut is poor. Cut is often considered the most important C.

ROUND DIAMONDS

The Round Cut diamond is by far the most popular shape available today. To maximize the brilliance of a Round Cut diamond, select one in the highest cut grades – ideal or very good. Also select excellent or very good polish and symmetry grades. For the most traditional Round Cut diamond look for a length to width ration of between 1.33 and 1.66. The Round Brilliant Cut is popular for many reasons, one being that it provides exceptional brilliance and a classic, ageless look. Round Brilliant Cut diamonds are stunning choices for engagement rings, necklaces and other fine pieces.

CUSHION CUT DIAMONDS

Cushion Cut diamonds are available in shapes ranging from square to rectangular. They have rounded corners and larger facets which increase their brilliance. For a square Cushion Cut diamond, look for a length to width ration of between 1.00 to 1.05. For a rectangular shape, look for a length to width ration greater than 1.15. With many cut options, choosing a Cushion Diamond offers creativity and personalisation. Cushions also have the luxurious appeal of a classic fashion along with modern fire and flair.

HEART SHAPED DIAMONDS

The Heart Shaped diamond is the ultimate symbol of love. The length to width ration will determine the diamonds outline (or how it would look from above). For a more traditional “hearty shape” diamond, look for a length to width ration of between 0.90 and 1.10. In addition to being a sign of romance, the Heart Shaped Diamond requires a premium cut, prolonging and possibly increasing its value over time.

EMERALD CUT DIAMONDS

What makes the Emerald Cut different is that it’s pavilion is cut with rectangular facets to create a unique optical appearance. If you would prefer an Emerald Cut with a squared outline, look for an Asscher Cut diamond. The length to width ration will determine the diamond’s outline. For a classic Emerald Cut, look for a length to width ration of between 1.30 and 1.40. Most notably, the Emerald Cut showcases size better than other diamonds of the same carat. Emerald Cuts are a premium choice for those desiring a larger piece without an enormous price tag.

PRINCESS CUT DIAMONDS

This is our most popular non-round diamond shape, especially for engagement rings. The Princess Cut has pointed corners and is traditionally square in shape. For a square Princess Cut diamond, look for a length to width ration of between 1.00 and 1.05. For a rectangular shape, look for a length to width ration that is greater than 1.10. The Princess Cut allows for a square outline while still offering nearly the same brilliance as the Round Brilliant Cut. Due to the larger yield maintained from cutting for a Princess, the price per carat is usually much lower than the Round Cut.

MARQUISE CUT DIAMONDS

The shape of a Marquise Cut can maximize the carat weight, resulting in a much larger looking diamond. This Brilliant Cut diamond looks beautiful with Round or Pear shaped side stones. The length of the cut makes fingers look long and slender. For the most traditional Marquise Cut diamonds, look for a length to width of 1.75 to 2.25. he Marquise’s elongated figure gives the appearance of a larger stone when compared to other shapes in the same carat. Making the fingers of the wearer look thinner and longer, the Marquise shines brightly and is usually noticed for its unique shape.

RADIANT CUT DIAMONDS

Trimmed corners are the signature of Radiant Cut diamonds which look beautifully set with either baguette or round side diamonds. For a square Radiant Cut diamond, look for a length to width ratio of between 1.00 and 1.05. For a rectangular shape Radiant Cut diamond, look for a length to width ratio that is greater than 1.10. Radiant’s are formed with many facets and angles, making them appear almost like cracked ice. Because of this, flaws and inclusions are easily hidden. The bevelled corners of Radiant Cuts allow for more stability—making it a wise choice for those with an active lifestyle.

TRILLION CUT DIAMONDS

Trillion Diamonds, also known as trilliant diamonds, are incredibly enchanting and unique. Different than round, square or rectangular shapes, the Trillion almost always makes an impression. The ideal length to width ratio for a Trillion is 1.0-1.10. The personality of the Trillion is perhaps its strongest asset. The sharp, unique features create a dashing look, maximized by the Trillion’s immense width. For this reason, Trillions tend to look larger than other diamonds of the same carat weight.

OVAL CUT DIAMONDS

Oval Cut diamonds have a long history, dating back as early as 1304. Today, they’re making a strong comeback and are a popular choice, particularly if you’d like your finger to appear longer and slimmer. Like round diamonds, ovals cut in the brilliant style exhibit excellent fire and brilliance. While always dependent on personal preference, the Oval Cut diamond is often appealing in a length to width ratio of 1.30-1.50. This fancy length diamond is durable because it carries no pointed edges. Ovals also have a lower price point than Brilliant Round Cuts while still maintaining the curved shape.

PEAR CUT DIAMOND

The Pear Cut is also known as a teardrop for its single point and rounded end. For the most traditional Pear Cut diamond, look for a length to width ration of between 1.45 and 1.75. The Pear Cut diamond is ideally suited to pendants and earrings as the shape accentuates the heck-line as well as the Décolletage area (a term used in woman's fashion referring to the upper part of a woman's torso, comprising her neck, shoulders, back and upper chest). The Pear Shaped also hides inclusions well.

COLOR

What it means

Color refers to how colorless a diamond is. The less color, the more rare and valuable the diamond.

After diamond cut, diamond colour is the second most important characteristic to consider when choosing a diamond. The highest quality diamonds are colourless, while those of lower quality have noticeable colour, which manifests as pale yellow in diamonds.

Diamond Color is graded in terms of how white or colourless a diamond is. The GIA grades diamonds from D to Z, with D being the most colourless, and Z containing noticeable brown or yellow tint.

The pricing of diamonds usually reflects these grades—sometimes significantly. In most cases, the naked eye cannot tell the difference between two adjacent colour graded diamonds, though the price difference may be significant.

The most critical aspect with Color is to determine if it appears colourless in relation to its setting. You also want to be certain that a diamond is clear of any tinting that takes away or interferes with white and coloured light reflections.

CLARITY

What it means

Clarity measures imperfections inside (inclusions) and on the surface (blemishes).

Due to the fact that diamonds are formed deep within the earth, under extreme heat and pressure; virtually all diamonds contain "birthmarks"; small imperfections inside the diamond (called inclusions), or on its surface (called blemishes).

Clarity refers to the degree to which these imperfections are present. Diamonds which contain numerous or significant inclusions or blemishes have less brilliance because the flaws interfere with the path of light through the diamond. The size of these impurities and imperfections determine the clarity grading of a diamond. Diamonds without such impurities are very rare.

The grading scale starts from Flawless / Internally Flawless (FL/IF), Very Very Slightly Included (VVS1/VVS2), Very Slightly Included (VS1/VS2), Slightly Included (SI1/SI2) to Included (I1, I2 and I3). 77 Diamonds does not sell diamonds below SI2 as they are not considered suitable for jewellery. Generally, diamonds below a VS2 grading are likely to have visible inclusions to the naked eye however this is on a stone by stone basis

CARAT

What it means

Carat measures how much a diamond weighs, not just how big it looks.

Instead of grams or kilos, diamonds are weighed in carats (not to be confused with gold’s Karat which signifies purity). This simply denotes a measuring scale where each 1 carat = 0.2 grams (0.50 carat = 0.1 gram and 5 carats = 1 gram).

Dimensions play an important role in the appearance of a diamond. In addition to the carat weight, the distance across the top of the diamond must also be taken into consideration. A common misconception is that half a carat is half the size of one carat. In fact, a half carat is half the weight of one carat, but the millimetre difference on a round stone is only 1.35mm. The average measurement for a 0.50ct stone is 5.00mm, while the average 1.00ct stone measures at 6.35mm.

While carat weight may indicate a diamond’s size, the shape and cut of a stone also play a large part in determining how large or small the stone appears. An elongated shape such as the Marquise cut may appear larger than a rounded shape such as the round brilliant even if the two stones share the same weight.

When comparing two stones of the same shape however, it is important to look at the cut grades and table and depth percentages, as shallower stones will tend to appear larger than deeper ones. Other aspects such as girdle width can also affect how large a stone appears, while not necessarily affecting the quality of the stone.