As the name suggests, shape (round, princess, radiant, etc.) describes a diamond's form, primarily as viewed from above. All diamond shapes have different attributes, but overall the beauty of the individual shapes is a matter of personal taste.
The cut of a diamond determines its brilliance. Put simply, the better a diamond is cut, the more sparkle it will have.
Almost all diamonds have tiny imperfections. Diamonds with few or no imperfections receive the highest clarity grades.
A diamond's colour grade actually refers to the lack of colour. In other words, diamonds that are white, containing little or no colour, receive higher quality grades than those with visible colour.