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The features of a diamond - The four "Cs "
In a diamond cut with the correct proportions the light is refracted from one facet to another of the pavilion. The light is refracted and once it goes through the crown it reproduces the several colours of the rainbow, as a consequence of its decomposition.
On the contrary, if the diamond is cut with a too deep pavilion, with the same diameter, it has a higher weighing in carats and its light can’t reach the other side of the pavilion or of the bottom.
If then the pavilion is not too deep, the light is refracted on the crown and dies away on the bottom of the diamond.
Cut
The cut is absolutely personal. The higher is the cut the better is the combination of colours, brightness, fire and sparkle. The cut is important, therefore it is necessary to be able to recognize it, it is merely a technical matter and the shape is a personal choice.
Colour
The colour is a subjective feature, a person may prefer one colour to another. Diamonds are available with white grading. The assessment is given by the approximation to the total lack of colour. Most rare ones are those with more lack of colour (D-E-F-G), while the greater part of diamonds are H-I-J-K rated. All the others, from L on, are more and more coloured. Most rare coloured diamonds are called “Fancy” and can be pink, blue, green or deep yellow.
- D, E, F = Uncoloured
- G, H, J, K = Almost uncoloured
- L, M, N, O = Faint yellow
- F, Q, R, S, T, U = Bright yellow
- V, W, X, Y = Light yellow
- Z = Strong yellow
In order to give you an idea, the following image shows diamond’s colour grading.
Clarity
Up to today there have never been in the world two identical diamonds. One is different from another because it contains small carbon traces or small crystals of different nature hold fast during the crystallization. In jargon, these types of impurity are called inclusions and are natural features. Their number, colour and size determine their clarity grade. Since usually they aren’t easily visible to the naked eye, these inclusions are observed through the microscope (with a 10X lens) by an expert who, once he discovers them, identifies the consistency and assigns to the diamond a clarity grade. The highest grade assigned is given by the total lack of carbon residues. Only a few very rare diamonds have this grade.
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Clarity Grade |
A diamond’s clarity is determined after an examination made by an expert through a 10X lens, spherically and chromatically corrected, with normalized light |
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CIBJO |
GIA |
Criteri di valutazione |
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Flawless |
Flawless |
The examination through the 10X lens reveals no internal and external inclusions |
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VVS |
VVS1
VVS2 |
Very small inclusions, very hard to be seen through a 10X lens |
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VS |
VS1
VS2 |
Very small inclusions, hard to be seen through a 10X lens |
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SI |
SI1
SI2 |
Tiny inclusions visible through a 10X lens, but still not visible to the naked eye if observed through the crown. |
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P1 |
I1 |
Inclusions almost invisible to the naked eye through the crown that do not affect the brightness |
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P2 |
I2 |
Inclusions more visible through the crown, slightly affecting the brightness of the precious stone |
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P3 |
I3 |
Many inclusions visible to the naked eye, of relevant size and highly affecting the brightness and consistency of the precious stone |
Carat Weight
The carat (from carob tree whose seed has the extraordinary property of weighing 200 milligrams) is the weight of a diamond. Therefore, 1 carat is equivalent to one-fifth of a gram, subdivided into 100 points. Consequently, a stone of 55 points weighs 0,55 carats (ct.). But the diameter and the weight are not standard, that is to say one-carat diamond does not absolutely have the same diameter. Diamond cutters are always trying to obtain different proportions, keeping the weight unchanged, in order to have the highest possible price.
Valoro Jewels guarantees its stones giving for each product a certificate that identifies the aforementioned features.
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