"Four Cs" of diamonds are considered as the most important grades and categories of diamonds. Clarity, Colour and Cut (proportion) are the quality elements which together with the Carat Weight determine the value of a stone. These attributes determine if the precious stone is worth more or less.

Cut : Diamond cut is the most important of the four Cs. Cut refers to the proportions, finish, symmetry, and polish of the diamond. It describes the manner in which a diamond has been shaped and polished from its beginning form as a rough stone to its final gem proportions. A well-cut gives a diamond its brilliance allowing the maximum amount of light to enter, reflect and return to your eye. Simply put, when looking at a diamond, if it doesn't catch your eye or if it doesn't flash in the light, it's probably not well cut.
Clarity : Clarity is an indication of a diamond's clarity and purity. It describes the degree to which a diamond is free of imperfections. Basically there are two types of flaws: external blemishes and internal inclusions. External blemishes refer to surface flaws and polishing defects. Inclusions refer to internal flaws and blemishes refer to surface flaws. The clarity of a diamond is graded by how many, how big and how visible the inclusions are, and where they are located within the diamond. The fewer and smaller the inclusions, the more rare and valuable the diamond.

Colour : A perfect diamond is completely colorless, and therefore it is most valuable and expensive. Colorless diamond allows more light to pass through it than a colored diamond. Diamond Colors range from intense yellow to brown, blue, green, pink and red. These fancy colors are rare and therefore more valuable. The Gemological Institute Of America has created a scale to measure diamond colour, ranging from D (colourless) to Z (yellow).

Colorless	Near Colorless	Faint Yellow	Very Light Yellow	Light Yellow
D,E,F	G,H,I,J	K,L,M	N,O,P,Q,R	S,T,U,V,W,X,Y,Z

Carat :The weight of a diamond and is expressed in Carats. 1 Carat equals 0.2 gram and there are 100 points in one carat. Thus a 50 point diamond is half a carat (0.50ct) and weights 0.1 gram. Because carat weight is a numerical value of weight, it is therefore possible for a diamond with smaller diameter to weigh the same or more than a diamond with a larger diameter. This is done by making the smaller diamond deeper or thicker and the diamond with the larger diameter is made shallower or thinner.The heavier the diamond, the greater the carat weight.