The shape you like best, such as round, pear or heart, is a matter of personal preference. The cut determines the diamond's brilliance. Cut - The cut of a diamond is the only factor that we, as humans, can control. An ideal cut allows the diamond's natural brilliance and fire to shine through. Color - A diamond's true color is determined by viewing it from its side under balanced white light.
Diamonds can range from colorless, which are extremely rare, to light yellow in color.
And sometimes we see a natural blue or yellow diamond which is also extrememly rare. Clarity - Most diamonds have natural inclusions. Inclusions are characteristics developed in the diamond during its formation such as lines. Diamond clarity is determined by the absence of these inclusions. Flawless diamonds are rare.