The Diamond 4С’s are the carat weight, clarity, colour and cut. All of these assessment factors help determine the value of a diamond and compare diamonds with each other.

The 4С’s rule was initially represented in the middle of the XX century, when the world first obtained a universal diamond quality determination tool providing a transparent method for establishing their value.

The diamond assessment considers four factors which are known as the 4 C’s:

DIAMOND COLOUR

One of the most important parameters is a diamond’s colour. It is the first thing which is assessed with the unaided eye and by which the external appearance of a diamond is judged. All diamonds may be divided into two main colour groups - colourless diamonds and fancy-colour diamonds (yellow, light blue, dark blue, red, green, pink and others).

Both the GIA (Gemological Institute of America) system and the Russian GOST R 52913-2008 system can be used to determine the colour.

The colour of a diamond is assessed in accordance with the International Colour-Grading System, from D through M, with D being the most colourless, and M being a most pronounced yellow.

D
E
F
G
H
I
J
K
L
M

DIAMOND WEIGHT AND SIZE

A carat is a measure of weight of gemstones, including, of diamonds. To understand the carat weight of a diamond is, it is necessary to consider it in conjunction with the other two criteria, i.e, the diameter of a diamond measured in millimetres, as well as proportions and symmetry of the diamond cut. For example, when viewed from above, diamonds with a bigger diameter of upper table look larger than the gemstones with a larger carat weight but a lesser surface of the table.

Diamonds are subcategorized into small-, medium- and large-sized:

  • Small: up to 0.29 ct
  • Large: from 0.30 ct.

Diamond weight and size correspondence:

Ct 0,05 0,10 0,20 0,25 0,30 0,40 0,50 0,70
Ø m⁄m 2,5 3,0 3,8 4,1 4,5 4,8 5,2 5,8
Ct 0,90 1,00 1,25 1,50 1,75 2,00 2,50 3,00
Ø m⁄m 6,3 6,5 6,9 7,4 7,8 8,2 8,8 9,4

DIAMOND CLARITY

Diamond clarity is a parameter that determines the number of inclusions in a specific gemstone. As the gemstone grows, inclusions and internal flaws may appear that could only be classified on tenfold magnification. Each inclusion emphasizes the individuality and uniqueness of a diamond and is at all times specified in a certificate, which allows to determine the value of the gemstone.

A diamond is considered flawless in the absence of any inclusions, whereas the availability of a number of inclusions have an impact upon the gemstone’s brilliance, as the inclusions prevent light refraction and reflection.

I.F.

Internally
Flawless

VVS1

VVS2

Very Very
Sighty Included

VS1

VS2

Very
Sighty Included

SI1

SI2

SI3

Sighty Included

I1

I2

I3

Included

Round
Oval
Marquise
Heart
Pear
Emerald
Radiant
Cushion
Princess

DIAMOND CUT AND DIAMOND CUT SHAPES

A cut is the most important parameter enabling to adequately reveal the entire beauty of the stone.

The essence of the cutting lies in emphasizing the diamond’s colour, positioning its edges at the definitely identified corners, which will enable the light to correctly reflect and refract within the diamond making it shiny and flawless.

There are different forms of diamond cut. The round cut is the most common and is regarded as classic or traditional, whilst all the other forms are called fancy.

Traditional fancy forms include the following: Princess, Marquise, Oval, Pear, Heart, Emerald and Radiant, as well as other options, such as Asscher and Baguette, have also been gaining popularity in the jewellery-making business.

Select a Diamond

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