The 4Cs of Diamond Quality

Buying diamonds can a simple or difficult process. If you have the budget for it, then the process is naturally simplified. Find the right jeweller (a big brand for example), communicate your wants, set aside a budget, and to find the right ring for you. A process that is especially true when it comes to diamonds: arguably the most sought-after precious stone. In reality, though, things tend to work out differently. If you are in the market for a precious diamond, and the only things you know about them is not that they are expensive and beautiful, we are here to clear things out for you. This post is meant to be an introductory but informative take on diamonds. There is much more to this precious stone. But these are the basics that you cannot do without. Learn about 4Cs that determine the value and beauty of diamonds.

Colour

The beauty of diamonds is related to the lack or absence of colour in the precious stone. Diamonds are judged on their ability to reflect light: and this capacity to do is a result of the “colourless” character of this precious stone. However, there is more to this. Diamonds unlike other precious stones like rubies, emeralds and sapphires, are known for their lack of character, and depending on the quality of the stone, are either predominantly or completely transparent character. This depends on several factors: like the cut and polish of the stone. However, the “colourless” character of this precious stone, varies between diamonds, going from colourless to diamonds that have an increasing shade of yellow. Thus, these difference in colour, or shade between different kinds of diamonds, are determined by the colour grading of diamonds, which is carried out according to a defined scale. One that is set by the Gemological Institute of America (GIA): the authoritative body that sets the standards when it comes to diamonds.

The GIA grades diamonds according to a D-Z scale: with D grade diamonds, being the most transparent, and hence the most valuable. Implying the absence of impurities that other elements contribute to an increasing shade of warmth, which adds to the colour tone to the precious stone. Thus, reducing its value. So as diamonds from ‘D’ (totally colourless) and get closer to ‘Z’ (an increasingly yellow to brownish shade), the value of the stone decreases. As the diamond’s hue increases, its ability to reflect white light decreases. So, the colourlessness diamonds fall under the spectrum. Going from the least colourless to those that have a warmer tone. With the relative value of the stone (other factors of the 4Cs considered) decreases.

To determine the true quality of a diamond (e.g., the difference between a diamond on the scale between D and E), it might be impossible to determine with an untrained eye and will require the services of a gemologist, who can study the stone under controlled lighting conditions, with right tools to determine its quality. However, the positive aspect of having less colour (or a colour tone) in diamonds should not be confused with coloured diamonds: diamond varieties come in distinct colours like blue, pink and even black. This is a separate category, which carries its own colour scales.

What matters when picking a diamond for its colour value, it is best to go for a stone that is close to the D-grade as possible. Which is often difficult owing to cost and rarity (or both). However, even lower grade (e.g., F-G diamond) can look great, if it is a stone with great cut and clarity.

Clarity

The clarity of the diamond is determined by the presence/absence of inclusions and blemishes in the stone. Inclusions refer to the presence of internal impurities, other trace elements, and breaks that affect the quality of the diamond. Blemishes on the other hand refer to the presence of external breaks, chinks and scratches that affect the overall quality of the stone. The presence of inclusions and blemishes affect the ability of light to pass through and reflect correctly from the diamond.  To determine the clarity of diamonds, the GIA has set a Diamond Clarity Scale. That contain 6 main categories. They are:

Flawless (FL)

A diamond that has no internal or external imperfections. Actually, it is impossible to find completely flawless diamonds. However, the flawless diamonds that have virtually no/little imperfections do exist. Importantly, they have no visible inclusions. However, they are rare and pricey.

Internally Flawless (IF)

Internally flawless diamonds are diamonds that contain blemishes and the presence of surface grains. But like FL diamonds, IF diamonds also do not contain inclusions. And are often considered as a premium choice.

Very, Very Slightly Included (VVS1 or VVS2)

Diamonds with a level of clarity contain minute inclusions. However, they are almost impossible to spot with the naked eye. And in practice, they can only be identified by a skilled gemologist. And for careful verification will requiring over 10x magnification.

Very Slightly Included (VS1 or VS2)

Going a step down from VVS1 and VVS2 we have very slightly included diamonds (VS1 and VS2). This category of diamonds contains visible and a slightly higher number of inclusions. However, don’t be discouraged by this. As noted almost all diamonds, no matter how rare and expensive, contain some imperfections. In fact, VS1 and VS2 are some of the most popular diamond choices. The difference between VS1 and VS2 is between the difficulty vs ease of dealing with these inclusions. And depending on the cut and polish are a great choice for diamond engagement rings.

Slightly Included (SI1 and SI2)

Slightly included diamonds carry more noticeable inclusions. Which can be determined with the aid of 10x magnification. Bear in mind, the inclusions present in SI1 and SI2 are not visible to the naked eye, unless you are dealing with an expert in the field. However, when it comes to SI2 some of the inclusions may be visible to the naked eye. A way to mitigate the effects of the inclusions to go for a larger stone (which is more affordable at this Clarity) and one that is well-cut. When going for Slightly Included diamonds, you should have an eye out for “twinning wisp”: Which are series of, often connected inclusions, like clouds and crystals. Diamonds of this grade are naturally cheaper.

Included (I1, I2 & I3)

As the name indicates, in Included diamonds, the internal blemishes, of whatever kind, are visible. And their visibility increases with an added number. With I2 and I3 having an increasingly higher level of visible inclusions. The latter two varieties are poor choices for diamond engagement rings.

Cut

 The key characteristic of diamonds is their ability to transmit light. The ability of this precious stone to glitter with great intensity under the presence of light is one of their main selling points. The quality of a diamond’s cut determines how well the diamond interact with light. A well-cut diamond can increase the light reflecting and refracting qualities of the stone, and hence increase its value. The cut of the diamond does not refer to the shape of the diamond: Such as oval, pear shape.

 The cut of a diamond is arguably the most important aspect of buying diamonds if it for an engagement ring or other jewellery. For if even if you have a high-grade diamond, with few inclusions, great clarity and colour, they can all be ruined by a poor cut. The cut refers to the proportions, symmetry and polish. The strength of each of these elements determines the quality of the cut of the diamond.

And these are graded according to five levels.

Excellent Cut

Diamonds that are graded as Excellent, in their cut, project the highest level of brilliance. The quality of the cut enables almost all incoming light to be reflected. These diamonds carry a brilliant sparkle.

Very Good Cut

The more realistic cut option. Very Good Cut Diamonds offer great brilliance: as most of the entering light that hits the stone reflected through the diamond’s facet. The difference between Excellent and Very Good diamond cuts are difficult to differentiate. And hence these are a great precious stone option.

Good Cut

Like Very Good Cut diamonds, Good Cut Diamonds also carry great sparkling capacity. With a lot of the light reflecting through the table to the viewer’s eye. These diamonds provide beauty at a lower price point.

Fair Cut

A weaker option. Fair Cut Diamonds offer less brilliance, as their ability to capture and reflect light in a way that accentuates the glitter of the stone is notably less. Fair Cut diamonds is a more suitable choice for accent stones.

Poor Cut

As the name indicates, these are sub-par option. They capture and emit little light. The poor cut means that light reflection is lost.

Carat

Carat is the unit of measure that is used to determine the weight of diamonds. A single carat is equal to 0.2 grams or 1/20^th of a gram. When it comes to diamond, the rule is, the heavier stone (greater the weight), and hence its price. When a diamond is cut, the challenge for the cutter is to maintain the weight and size of the original stone, whilst adding a cut that increases its sparkle. Which, with progression (i.e., more cuts to shape it), will progressively reduce its value. So, it is a balancing game when it comes to getting a great cut and with high carat diamond is the way forward.

Anatomy

A relatively more obscure part of diamond grading, for those less knowledgeable. The anatomy of a diamond is studied by measuring a number of different factors. However, it is critically linked to the cut and carat of the diamond and how these factors affect each other. For starters, the anatomy of a diamond is understood by analyzing the following factors: Total Depth, Pavilion Depth, Pavilion Angle, Crown Height, Crown Angle, Girdle Thickness, Lower Girdle / Half Facet Length, Culet etc. These terms may seem alien to the new user, and in fact, they are. The key factor is to understand these elements in relation to 4Cs. The specific information is best understood with aid of an expert gemologist.

Complete GIA 4Cs Guide