Most of the times forgotten or ignored ‘C’ is the cut of a diamond which ensures brilliance and sparkle of the gemstone. Cut is used to grade a stone for its overall appearance. For a non technical person, very simply, if a diamond cannot catch your eye or attracts you in a flash time, it is not a good cut. A piece of diamond cut perfectly blinds you with its charm. A skilled master cutter can only get the perfect cut diamond from the raw or rough. The way and volume of sparkle of a diamond are purely based upon its cut. Reflection of light is always maximum in a well cut diamond piece and therefore it sparkles at its best. The light escapes towards the sides or the bottoms in shallow cut and deep cut diamonds. Hence, their sparkle also gets affected. The traditional round brilliance diamond is the only type where in we can define range of proportions which can result in to a well-cut. The same kind of range of proportion is not available for fancy shape diamonds like princess cut, pear, emerald etc. CUT and SHAPE are two different confusing terms. SHAPE means outward look of the diamond such as round, oval, emerald and more while CUT means reflective qualities of the diamond. When looking at the proportions of a diamond, a trained eye would distinguish between an Ideal cut and a Deep or Shallow cut. The cuts are usually defined by terms like Ideal Cut, Premium Cut, Fine Cut, Good Cut, Fair Cut, and Poor Cut. Ideal, premium, fine and good cut diamonds are of more value as they reflect most of the light. Fair and poor cut diamonds reflect only a portion of the light enters. The Ideal, Premium, Fine and Good cut grades vary respectively, from maximum brilliance, to reflecting most of the light that enters the diamond. Diamond proportions graded as Fair or Poor mean that the diamond reflects only a fraction of the light that enters it.