"The diamonds available to us today are Sawn Rough and Makeable Diamonds. The Sawn Rough Diamonds constitute about a meager 5% sustaining a Nature's premium when compared to the widely used makeable diamonds which constitutes the remaining 95% of diamonds available. The Sawn Rough holds a unique composition (crystal formation) and when cut to perfection it becomes incomparably brilliant."
Diamonds are chosen based on their 4c characteristics (Cut, Color, Clarity and Carat).
Cut: A diamond cut to perfection is absolute in its brilliance. Among all the characteristics of a diamond 'cut' alone is a quality that humans have the privilege to work, 'to create a marvel'. This also translates into the fact that even if a diamond has all the innate propensities to exude brilliance it's true splendor is revealed only in the expert hands of a diamond cutter.
There are numerous shapes to which a diamond can be cut. Among them the best shape wherein a diamond exhibits the finest of its traits in terms of cut and produces maximum brilliance and fire is a 'round brilliant cut'.
Color: The color grading system given by the Gemological Institute of America (GIA) gives a scale that begins from D (colorless) and ends at Z (light yellow) with a color grade of D signifying the highest possible and the whitest or colorless.
Clarity: Clarity is a measure of minute imperfections that appear in diamonds. These imperfections, also called as inclusions and blemishes speak volumes about the clarity of a diamond. Inclusions refer to crystals, clouds and feathers within a diamond while blemishes refer to the external flaws like surface irregularities.
Diamonds without inclusions are considered very rare. Clarity is classified according to the nonexistence of these imperfections in a diamond (wherein it is called flawless) and it is further classified according to the level of visibility of these imperfections (Refer chart).
The Gemological Institute of America (GIA) gives a scale ranging from FL (Flawless) to 12-13 (Included) for measuring clarity.
Carat: Carat refers to the weight of the diamond. It is said that a million diamonds must be mined to produce a single carat of polished diamond. You may also observe that nearly 40-60% of the rough is lost in the process of cutting a diamond. (1 carat (ct.) = 200 milligrams)
The carat is also associated with the size of the diamond. The bigger the diamond higher is its value.