A diamond’s beauty is not determined by the values on its certificate

Diamonds can often be very intimidating; leaving the consumer overwhelmed and confused. Jewellers can often mislead the consumer and persuade the consumer into buying something that they don’t fully understand, at a pretty penny. If you have insight on the product, your understanding of the product’s specifications and price will be meaningful and empowering.

The 4C’s is an age old concept that everyone has encountered when purchasing diamonds, namely: cut, carat, colour and clarity, in no specific order. I say this because, it all depends on what is more important to you. If carat is more important (which is the general trend among women; size does matter boys), then you can compromise on colour and clarity to stay within a given budget. If clarity is more important and size is unimportant to you, then you can compromise on carat to stay within a given budget. If both colour and carat are important, then one can compromise on clarity. The combination of the 4C’s equals the 5th C, cost. Cost will be discussed throughout the article. Always remember:  a diamond’s beauty is not determined by the values on its grading certificate, just as its beauty is not determined by the amount of money you spend on it. 

But what exactly do all these terms mean!? Here is an extensive guide that will educate you on the product, so that you can feel confident in the money that you are lying out. It is also important to acknowledge that a diamond is not an investment piece, but an eternal symbol of your love to your other half. So yes, if you consider time, it is can be seen as an investment, because your spouse will be wearing it for the rest of their life, but one cannot approach a symbol of eternal love as an investment. (because you will most likely never sell it).


Cut is definitely the single most important factor to consider when purchasing a diamond. The quality of a diamond’s cut results in the sparkle and fire of a diamond. A diamonds of high quality (colour and clarity) with a poor cut will result in a diamond that is dim and lacks fire.

In general, the word ‘cut’ is used to refer to the shape of a diamond, for example: round, marquise, oval, etc. Some diamond shapes appear larger than others even though they have the same carat weight. Shapes that generally appear larger than their carat weight are pear, oval and marquise cuts – these appear larger than round cut diamonds for the same carat weight. Shapes that generally appear smaller than their carat weight are square cut diamonds like princess, asscher and emerald cuts – these appear smaller than round cut diamonds for the same carat weight.

Cut isn’t merely the shape of a diamond, but, also refers to the quality of a diamond’s cut. The quality of a diamond’s cut is determined by various ratios in a diamond’s anatomy, such as: table (top of the diamond), depth (top to bottom), crown height, pavilion depth, crown angle, pavilion angle, girdle thickness, etc. The most important of these being depth, table and diameter, as the ratio of the depth to diameter and table to diameter are prominent in determining a diamond’s cut grade. The final grading of a diamond’s cut quality also takes the symmetry of the facets and polish into account. A round brilliant cut diamond is cut with 57 facets; some with a 58th facet known as the cutlet, which is located at the bottom of the pavilion. An ‘excellent’ cut means that the ratios are nearly perfect, allowing incoming light to reflect directly back, out of the table of the diamond, resulting in a diamond with beautiful lustre, sparkle and fire. A ‘poor’ cut means that a diamond is cut is too shallow or too deep, the light entering the table of the diamond is directed in a different angle. The stream of light either goes straight through the diamond (generally cut too shallow) or out through the side of the diamond (generally cut too deep). This prevents any light from reflecting back through the top of the diamond, resulting in a diamond that is dim and lacks sparkle. A diamond with this kind of low quality cut is said to “leak” light.

It is also important to note that there are numerous ratio combinations possible within the grading scale of excellent, very good, good, fair to poor, but also within a single grade category. This prompts the topic of diamond ‘spread’. The spread of a diamond refers to its size compared to its carat weight. A ‘spready’ diamond is cut slightly shallower resulting in a larger table, therefore, facing up larger than its carat weight (when observing it from the top) but will have a shallower pavilion (when observing it from the side). These diamonds aren’t necessarily ‘poor’ cuts as the ratios can still result in a ‘very good’ to ‘good’ cut grading, inhibiting beautiful brilliance and fire, but face-up larger than their carat weight. To put it into perspective, one can imagine two people of the same weight e.g. 70 kg, but of different height e.g. 1.6 m vs. 1.7 m tall. The 1.7 m person will appear to be a much larger person due to the added length. A diamond with a ‘poor’ quality cut will result in a diamond that faces-up much smaller than its carat weight (when observing the table of the diamond from the top), as most of the weight will be portioned to the pavilion of the diamond (when observing it from the side). The added weight on such a diamond will also reduce the diamond’s brilliance and lustre as it causes light to leak from the side of the diamond.

Avoid compromising for cut grades lower than ‘very good’ to save on the budget. It is best to compromise on colour or clarity.


Carat is commonly mistaken for the size of a diamond but in actuality refers to the weight of a diamond, which is generally proportional to the size of a diamond. One carat is equivalent to 0.2 grams or 200 milligrams; about the weight of a paperclip. The modern carat system and the word ‘carat’ originated from the very uniform carob seed, which was used as a counter balance on the scales of old gem traders. A 0.15 ct diamond is referred to as a 15 pointer and a 0.95 ct diamond a 95 pointer, etc. Diamonds above 1 ct are referred to as a ‘two point oh four carats’ (2.04 ct), for example. This allows for very accurate measurements as a carat can be divided into a hundred points, therefore, to the hundredth decimal place. The weight of a diamond is measured to a thousand decimal places (0.001), which is rounded to the nearest hundredth decimal place.

Carat weight is not the only determining factor in the value of a diamond; two diamonds of equal carat weight will have unequal value as the value is also dependent on the clarity, colour and the cut quality of the diamond. Two ½ carat diamonds will not have the same value as a 1ct diamond (assuming all other factors are the same); the greater the weight of the diamond, the more rare it becomes, hence the increase in value.

It is an obvious trend that the price of a diamond increases with increase in carat for the same given colour, clarity and cut. A diamond with a bad quality cut, one that is cut too deep, will result in a diamond that appears much smaller than its given carat weight as most of the weight is portioned to the pavilion depth (‘cone’) of the diamond. The added weight on such a diamond will also reduce the diamond’s brilliance and lustre. The same applies to a diamond that is cut too shallow, it will appear much larger as the weight is portioned to the table (top) of the diamond, but it will lack brilliance. However, a diamond that is cut slightly shallow, but still qualifies as a very good to good quality cut, will appear larger than its given carat weight and will still sparkle beautifully. This is referred to as ‘spread’; a ‘spready’ diamond will appear much larger than its carat weight, as most of the weight is portioned to the table (top) of the diamond (this will be discussed more extensively in the next post). One can roughly estimate the size of a diamond according to its carat, but, that is solely dependent on the quality of the diamond’s cut.

Budget hack: if you have a specific carat weight in mind, aim for just below that carat weight e.g. 2ct, opt for 1.90-1.99ct. You will not be able to notice the small difference in the diamond’s size, but this will allow you to save a significant amount of money. One should avoid ‘magic sizes’ which are ½, ¾ and 1 ct. These weights are thresholds for diamond pricing, above these weights the price per carat increases significantly. These weights coincide with popular diamond weights, as with anything, popularity results in demand which results increased prices. For example, two diamonds are exactly the same colour, clarity and cut. The one weighs 1.03 ct and the other 0.97 ct, the 0.06ct (6 pt) weight difference is visually undiscernible, but the difference in price can be up to 20% more. 


The diamond colour grading scale is between D (colourless) to Z (light yellow). Before this grading system existed, there were various other loosely applied systems, which made use of the beginning of the alphabet, roman numerals etc. Thus, GIA chose the letter D as the starting point to fully dissociate itself from the other archaic, inconsistent and inaccurate grading systems. The more colourless a diamond, the more expensive it is. The opposite is of course true for fancy colour diamonds, which increase in value with increase in colour saturation. Fancy colour diamonds are extremely expensive and rare as only every 1 in 10 000 carats is fancy colour. Qualified diamond graders determine diamond colour under precise viewing conditions and controlled lighting by comparing them to stones of known colour, or by years of experience. To the untrained eye, many of the colour distinctions between grades are subtle and unnoticeable, but the difference in diamond price and quality can be vast.

Similar to clarity, one can save quite a chunk of your budget with colour – it’s all about how you set it and what colour metal you choose. D colour diamonds are extremely expensive because they are completely colourless, therefore very rare. Where M colour diamonds, which fall into the “faint yellow category” for example, are less expensive and can still face-up white in colour. A diamond’s colour is determined by turning it face down on a white surface, this saturates the colour in the pavilion of the diamond to allow for accurate grading, but, when turned face up a diamond’s colour is less saturated and faces-up more white in colour than its grading.

The best value for money without compromising on colour are diamonds within the ‘near colourless’ grading class G-J. Diamonds in the K-M ‘faint yellow’ category are also good budget savers, but these should preferably be set in rose or yellow gold to neutralize the colour of the diamonds; they will appear much whiter than their grading, sometimes by 3 colour grades. The cost saving in these categories can be very significant compared to colourless diamonds between D-F. Colourless stones are more complimented by white gold and platinum settings to enhance the very white appearance of these diamonds; setting these colourless stones in yellow gold may show through the colour of the gold. Some diamond shapes also show colour more shyly than others. The more brilliant cut stones such as cushions, pears, ovals and radiants show colour less distinctly than step cut diamonds such as emeralds and asschers; these cuts have larger facets which reflect more colour. The size of the diamond will also influence the saturation in colour as larger stones, over 1 ct, show colour more easily.  A colour grading lower than H for a stone larger than 1 ct may be unfavourable. Beauty, however, is in the eye of the beholder; and there is no way to predict how a diamond will appear in a certain setting or a certain cut.


Diamonds were formed in four natural processes 1. In the earth’s mantle (commercial diamond mining), 2. In subduction zones (rocks subducted into the earth’s mantle during plate tectonic movements), 3. At asteroid impact sites, 4. In space (some meteoroids contain nano-diamonds). The majority of diamonds were formed at about 150-200 kilometres under the earth’s surface in its mantle; where temperatures are between 900-1200 Celsius and the pressure 45-60 kilobars (50 000 times more than atmospheric pressure). It is thought that these diamond stability zones, where diamonds were formed and stored, are mainly under the interiors of continental plates. Rare, deep-source volcanic eruptions, unobserved by the modern human, carried these diamond deposits near the earth’s surface. During these volcanic eruptions once the magma (kimberlite and lamproite), carrying diamond containing rocks, had erupted through the earth’s surface and cooled down, kimberlite and lamproite pipes were formed. These pipes are where most of the world’s diamonds are found. Bearing this incredible natural phenomenon in mind, one can have better insight on the flaws that a diamond may inhibit. We can think of these flaws as birthmarks.

The clarity of a diamond refers the purity of a diamond, which declines with the increase in natural inclusions found in a diamond. Flawless diamonds that are without any natural inclusions are extremely rare, therefore, extremely pricey. These inclusions manifest in many different forms such as: pinpoints, clouds, needles, knots, crystals, feathers, cleavages, internal grains, twinning wisps, indentations, cavities and chips – a mouthful. But, what do these actually look like and do they really matter? Although inclusions take on many different forms and grading categories, it is not necessarily such a negative thing. Firstly, most imperfections up to SI2 cannot be seen with the naked eye, i.e. they are only noticeable to the trained eye under a 10x magnification diamond loupe. Secondly, you can save a lot of money by opting for an imperfect diamond, which still appears perfect to the naked eye. No, Jealous Jenny’s will not be able to notice these imperfections (SI1 or higher grading) in your diamond when you are showcasing your brand new sparkler. In fact, some I (Included) graded diamonds may also be eye clean, depending on the location of the inclusions. Thirdly, it can also be used as an identification tool. If you get to know your diamond and know exactly where these inclusions are and what form they take, you will easily be able to identify your diamond. Fourthly, inclusions also make diamonds unique; no other diamond will ever be the same as your diamond, as no two diamonds will have exactly the same type of inclusion in the same place. Unless you’re a big baller and money is no object, opt for diamonds that aren’t flawless to get more bang for your buck.

When diamonds are graded under 10x magnification by a skilled grader, the quantity, size, nature, position and colour of the inclusions are considered. There are 11 possible categories in which a diamond’s clarity can fall:

*NB to remember that this is under 10x magnification*

  • Flawless (FL): no blemishes or inclusions are visible
  • Internally Flawless (IF): only blemishes and no inclusions are visible
  • Very, Very Slightly Included (VVS1 and VVS2): inclusions are difficult to see
  • Very Slight Included (VS1 and VS2): minor inclusions that can range from difficult to somewhat easy to see
  • Slightly Included (SI1 and SI2): inclusions are noticeable
  • Included (I1, I2, and I3): inclusions are obvious which may affect brilliance and transparency