The 4Cs

Every diamond is unique, each with its own colour, shape and size. To determine their precise value, each diamond is graded according to the 4Cs – colour, clarity, cut and carat weight. These are the accepted standards for assessing the quality of a diamond. Only diamonds with the ideal combination of the 4Cs are selected to be set in Bellagio jewellery.


The quality of a diamond’s cut is determined by evaluating the symmetry, proportion and polish of the stone. Ultimately, an excellent quality cut brings out the best sparkle; facets that are cut to the perfect proportions with precise symmetry will refract and disperse light with maximum brilliance and scintillation.

Two diamonds may have the same colour, carat weight and clarity, but if their cut grades differ, one would be more brilliant and spectacular than the other. Therefore, it is very important to pay special attention the cut quality of your diamond.


Clarity pays attention to the purity of the diamond.  This is a study of a diamond’s inclusions (internal flaws) and blemishes (external imperfections) under 10-power magnification. Grades range from Internally Flawless (IF) and Very Very Slightly Included (VVS) to Included (I – which is visible to the naked eye). The clarity grade is determined by the number of inclusions and blemishes, their size as well as their position in the diamond.


Most diamonds are white with a slight yellow tint. The colour grade measures the intensity of this tint. Colourless diamonds are considered the most valuable. The international standard for grading the ‘colourlessness’ of a diamond is through an alphabetical scale from “D” (colourless) to “Z” (light yellow).


Carat refers specifically to the weight of a diamond and not its size or dimensions (these are determined by the cut quality). Diamonds are measured to 1/1000th of a carat; one carat is equal to .20 grams. Only one in a million diamonds mined weighs 1.00ct!