PurelyDiamonds > The 4 C´s
The Four Cs – And why they're important for you
Every diamond is unique. To calculate its value, experts refer to what they call the Four Cs--Colour, Clarity, Cut and Carat. All of these factors will influence the eventual value of the diamond.
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· The Colour
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· The Clarity
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· The Cut
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· The Carat
The Colour
Colour Grades used by Purely Diamonds –
A diamond can divide light in to a spectrum of colours (like a prism). Colour in a diamond acts like a filter and diminishes the spectrum of colours emitted. The less colour in the diamond, the better the colour grade.
The scale for grading ranges from D which is totally colourless, to Z which is a pale yellow or brown colour. Diamonds that are ‘colourless’ (graded D, E or F) are very rare and demand premium prices. The untrained eye will find it very difficult to distinguish between D, E or F grades.
G, H, I and J are ‘near colourless’ and represent excellent value for money. G and H are sometimes called ‘rare white’ and are the most sought after in the ‘near colourless’ group.
The majority of diamonds we use are colour ‘G’ or above. As you can see, colour G is the 4th highest colour and top of the ‘near colourless’ group. This grade represents great value for money, as ‘colourless’ stones can be very expensive (less than 2% of all diamonds are graded as colour D).
The Clarity
This tells us whether a diamond is flawless—i.e. without any imperfections—or whether there are what the experts call inclusions, small imperfections which are often not visible to the naked eye. In effect, clarity is a measure of the diamond's purity. The majority of diamonds we use are clarity ‘SI1’ or above, which means these natural imperfections are completely invisible to the naked eye. You won’t see any marks in your diamond at all.
IF to VS can be described as luxury grades. Inclusions are difficult to see when using a 10x magnification in good light, and are not visible with the naked eye. Any diamond graded between IF and VS should be sparkly and bright, and within these grades diamonds suffer no noticeable loss of brilliance through reduced clarity.
SI1 and SI2 grades represent excellent value for money. The small inclusions are fairly easy to see under 10x magnification, and there may be some barely noticeable lack of brilliance in comparison. However, you cannot see these small inclusions with the naked eye. Any diamond in these grades will also be bright and sparkly. Untrained individuals will not see the difference between a VS and an SI graded diamond, either in terms of inclusions or brilliance, without using magnification.
P1 Diamonds which fall into the Piqué bracket (P1), by definition have inclusions which can be visible to the naked eye. However, in P1 stones the inclusions should be difficult to see, or very minor, and Purely Diamonds only use P1 stones with inclusions that are not visible to the naked eye. We select the best P1 diamonds so that although they do fall in to the Piqué bracket, you won’t see any marks in your diamond with the naked eye.
· The Colour
· The Clarity
· The Cut
· The Carat
| GIA | UK | Description | Clarity |
| IF VVS1 VVS2 VS1 VS2 SI1 SI2 I1 I2 I3 |
Loupe Clean VVS1 VVS2 VS1 VS2 SI1 SI2 I1 - Piqué1 I2 - Piqué2 I3 - Piqué3 |
Internally Flawless Very Very Small Inclusions Very Very Small Inclusions Very Small Inclusions Very Small Inclusions Small Inclusions Small Inclusions First Piqué Second Piqué Third Piqué Spotted Heavily Spotted Rejection |
Internally Flawless No Visible Inclusions No Visible Inclusions No Visible Inclusions No Visible Inclusions No Visible Inclusions No Visible Inclusions Barely Visible Inclusions Easily Visible Inclusions Very Easily Visible Inclusions Heavily Included Very Heavily Included Near Gem |
The Cut
When diamonds come from the earth, they look nothing like the polished and cut gems you expect to see in fine jewellery. A lot of work goes in to turning these rough diamonds into perfect works of fiery brilliance. Cut and Shape are often confused - Shape refers to the outward appearance of the diamond (such as round, emerald, princess etc). Cut refers to the reflective qualities of the diamond.
• Cut
When a diamond is well-cut, light enters through the table of the diamond, travels to the pavilion and reflects from one side to the other before reflecting back out of the diamond through the table. This light creates a flashing effect that we know as brilliance/sparkle.
Cut is described with the following grades -
• Ideal, Excellent, Very Good, Good, Fair, and Poor.
Some diamond certificates do not specifically state the ‘Cut’ grade of the diamond. As we use a variety of independent certificates (AnchorCert, GIA, IGI and HRD) we cannot guarantee that the cut grade will appear on your certificate. It bears no reflection on the quality of the stone you have purchased if your certificate does not state the grade, as your diamond will always be ‘Good’ or better (the majority being Very Good and Excellent, some Ideal). It requires a trained eye to judge the quality of a diamond cut, and our in-house diamond graders are highly qualified professionals who only select diamonds that they grade as ‘Good’ or better, nearly always selecting ‘Very Good’ or ‘Excellent’. Your diamond will be well-cut, bright and sparkly, we guarantee it!
• Shape
The Carat
The carat is a measurement of weight, not size. Diamonds are actually valued in terms of their weight, not in terms of their size. The actual size of a diamond can be described in millimetres, please refer to this diamond size chart for conversion between carat weight and millimetres.
Note – do not confuse 'carat weight' with 'carat/karat' which is the method of determing the purity of gold (e.g 18ct white gold, 18ct yellow gold).
One carat is divided into 100 points – a diamond that is ½ a carat is also 50 points. Carat weight affects the price of a diamond more than any other of the 4 C's. A diamond that is twice the size of another, can be as much as 4 times the price. Larger diamonds are discovered less often than smaller diamonds, which means large diamonds are rare and have greater value. For this reason, the price of a diamond rises exponentionally to its size.
When deciding what size diamond to buy, there are a few things to consider:
| • | Your budget – some people suggest 1 - 2 months salary, others whatever you can comfortably afford. There are no strict rules, and it really does come down to what you are comfortable with. |
| • | Size vs Quality – if your partner prefers larger items of jewellery, and you are working with a budget, you can purchase a larger diamond which is graded slightly lower in terms of clarity and colour. For example, a 0.50ct D VVS1 (luxury grade) will be more expensive than a 0.70ct G SI1 (excellent value grade), even though it is smaller. Opt for the 0.70ct if you think your partner would prefer size over colour and clarity. |
| • | Finger size – slender fingers make smaller diamonds appear larger. A 1-carat diamond will seem proportionately large if worn by someone with very slim fingers. |
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