Cut
Like most things in life it is the form of that particular thing which would make it visually appealing. So too in diamonds.This spectacular gemstone in its rough form would look much like stone or glass. But it is only after the expert hand of a cutters touch; the stone would give way to such a beautiful gem. Much like the story of King Midas where in everything he touched turned to gold.
The amazing sparkle and shine in a diamond is attributed to its hardness and willingness to catch on good polish. Of the 4C's of Diamonds, Cut is the only C, which is determined by man.The simple theory where Diamonds is concerned is that all the light that enters the stone should exit the stone from the same area and return to viewer's eye.
In Diamonds a good balance between Brilliance and Dispersion is what makes this gemstone beautiful Brilliance :: A singular flash of Light from the biggest facet of a Diamond i.e. Table.Dispersion :: Multiple flashes of Light from the other smallest facets. Much like the twinkling of stars on a dark clear side.