Diamond Quality

The 4Cs of Diamond Quality

Recognising the need for standards in the diamond industry, GIA (Gemological Institute of America) developed a universal diamond grading system called the 4Cs - Cut, Colour, Clarity and Carat. The same grading system is used for both natural and lab-grown diamonds.


Cut determines how well a diamond facets interact with light.

Ideal and excellent cut diamonds allow a large percentage of light to be reflected into our eyes, resulting in optimum scintillation. A poorly cut diamond (too deep/too shallow) allows light to escape. As a result, the diamond will appear dull and lifeless.

The 4Cs - Cut
The 4Cs - Cut


Colour refers to the colour tint or hue in a diamond.

All diamonds have a yellowish tinge due to traces of Nitrogen. The closer the diamond is to colourless, the higher the value of the diamond. Graded on a scale between D (colourless) - Z (light yellow), Éclat by Oui selects diamonds from the D/E/F colour range.

The 4Cs - Colour
The 4Cs - Colour


Clarity refers to the absence of inclusions and blemishes on a diamond.

Inclusions impedes the refraction and reflection of light. Here at Éclat by Oui, we only select diamonds from the VS2+ range.

The 4Cs - Clarity
The 4Cs - Clarity


Diamond carat weight measures how much a diamond weighs. 

With all things being equal, a diamond of a larger carat size will cost more. This is because larger diamonds are rarer.